3312 lines
105 KiB
C++
3312 lines
105 KiB
C++
// Copyright 2010-2012 Google
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// Array Expression constraints
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#include <string.h>
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#include <algorithm>
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#include <string>
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#include <vector>
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#include "base/integral_types.h"
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#include "base/logging.h"
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#include "base/scoped_ptr.h"
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#include "base/stringprintf.h"
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#include "constraint_solver/constraint_solver.h"
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#include "constraint_solver/constraint_solveri.h"
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#include "util/string_array.h"
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namespace operations_research {
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namespace {
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// ----- Tree Array Constraint -----
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class TreeArrayConstraint : public CastConstraint {
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public:
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TreeArrayConstraint(Solver* const solver,
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const std::vector<IntVar*>& vars,
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IntVar* const sum_var)
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: CastConstraint(solver, sum_var),
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vars_(vars),
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size_(vars.size()),
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block_size_(solver->parameters().array_split_size) {
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std::vector<int> lengths;
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lengths.push_back(size_);
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while (lengths.back() > 1) {
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const int current = lengths.back();
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lengths.push_back((current + block_size_ - 1) / block_size_);
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}
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tree_.resize(lengths.size());
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for (int i = 0; i < lengths.size(); ++i) {
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tree_[i].resize(lengths[lengths.size() - i - 1]);
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}
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DCHECK_GE(tree_.size(), 1);
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DCHECK_EQ(1, tree_[0].size());
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root_node_ = &tree_[0][0];
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}
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string DebugStringInternal(const string& name) const {
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return StringPrintf("%s(%s) == %s",
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name.c_str(),
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DebugStringVector(vars_, ", ").c_str(),
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target_var_->DebugString().c_str());
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}
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void AcceptInternal(const string& name, ModelVisitor* const visitor) const {
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visitor->BeginVisitConstraint(name, this);
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visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
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vars_.data(), vars_.size());
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visitor->VisitIntegerExpressionArgument(ModelVisitor::kTargetArgument,
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target_var_);
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visitor->EndVisitConstraint(name, this);
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}
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// Increases min by delta_min, reduces max by delta_max.
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void ReduceRange(int depth, int position, int64 delta_min, int64 delta_max) {
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NodeInfo* const info = &tree_[depth][position];
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if (delta_min > 0) {
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info->node_min.SetValue(solver(), info->node_min.Value() + delta_min);
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}
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if (delta_max > 0) {
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info->node_max.SetValue(solver(), info->node_max.Value() - delta_max);
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}
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}
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// Sets the range on the given node.
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void SetRange(int depth, int position, int64 new_min, int64 new_max) {
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NodeInfo* const info = &tree_[depth][position];
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if (new_min > info->node_min.Value()) {
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info->node_min.SetValue(solver(), new_min);
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}
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if (new_max < info->node_max.Value()) {
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info->node_max.SetValue(solver(), new_max);
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}
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}
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void InitLeaf(int position,
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int64 var_min,
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int64 var_max) {
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InitNode(MaxDepth(), position, var_min, var_max);
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}
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void InitNode(int depth,
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int position,
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int64 node_min,
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int64 node_max) {
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tree_[depth][position].node_min.SetValue(solver(), node_min);
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tree_[depth][position].node_max.SetValue(solver(), node_max);
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}
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int64 Min(int depth, int position) const {
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return tree_[depth][position].node_min.Value();
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}
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int64 Max(int depth, int position) const {
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return tree_[depth][position].node_max.Value();
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}
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int64 RootMin() const {
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return root_node_->node_min.Value();
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}
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int64 RootMax() const {
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return root_node_->node_max.Value();
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}
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int Parent(int position) const {
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return position / block_size_;
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}
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int ChildStart(int position) const {
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return position * block_size_;
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}
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int ChildEnd(int depth, int position) const {
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DCHECK_LT(depth + 1, tree_.size());
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return std::min((position + 1) * block_size_ - 1, Width(depth + 1) - 1);
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}
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bool IsLeaf(int depth) const {
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return depth == MaxDepth();
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}
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int MaxDepth() const {
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return tree_.size() - 1;
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}
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int Width(int depth) const {
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return tree_[depth].size();
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}
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protected:
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std::vector<IntVar*> vars_;
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const int size_;
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private:
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struct NodeInfo {
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NodeInfo() : node_min(0), node_max(0) {}
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Rev<int64> node_min;
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Rev<int64> node_max;
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};
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std::vector<std::vector<NodeInfo> > tree_;
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const int block_size_;
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NodeInfo* root_node_;
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};
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// ---------- Sum Array ----------
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// Some of these optimizations here are described in:
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// "Bounds consistency techniques for long linear constraints". In
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// Workshop on Techniques for Implementing Constraint Programming
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// Systems (TRICS), a workshop of CP 2002, N. Beldiceanu, W. Harvey,
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// Martin Henz, Francois Laburthe, Eric Monfroy, Tobias Müller,
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// Laurent Perron and Christian Schulte editors, pages 39–46, 2002.
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// ----- SumConstraint -----
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// This constraint implements sum(vars) == sum_var.
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class SumConstraint : public TreeArrayConstraint {
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public:
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SumConstraint(Solver* const solver,
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const std::vector<IntVar*>& vars,
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IntVar* const sum_var)
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: TreeArrayConstraint(solver, vars, sum_var), sum_demon_(NULL) {}
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virtual ~SumConstraint() {}
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virtual void Post() {
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for (int i = 0; i < size_; ++i) {
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Demon* const demon = MakeConstraintDemon1(solver(),
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this,
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&SumConstraint::LeafChanged,
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"LeafChanged",
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i);
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vars_[i]->WhenRange(demon);
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}
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sum_demon_ = solver()->RegisterDemon(
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MakeDelayedConstraintDemon0(solver(),
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this,
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&SumConstraint::SumChanged,
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"SumChanged"));
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target_var_->WhenRange(sum_demon_);
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}
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virtual void InitialPropagate() {
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// Copy vars to leaf nodes.
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for (int i = 0; i < size_; ++i) {
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InitLeaf(i, vars_[i]->Min(), vars_[i]->Max());
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}
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// Compute up.
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for (int i = MaxDepth() - 1; i >= 0; --i) {
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for (int j = 0; j < Width(i); ++j) {
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int64 sum_min = 0;
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int64 sum_max = 0;
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const int block_start = ChildStart(j);
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const int block_end = ChildEnd(i, j);
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for (int k = block_start; k <= block_end; ++k) {
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sum_min += Min(i + 1, k);
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sum_max += Max(i + 1, k);
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}
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InitNode(i, j, sum_min, sum_max);
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}
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}
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// Propagate to sum_var.
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target_var_->SetRange(RootMin(), RootMax());
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// Push down.
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SumChanged();
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}
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void SumChanged() {
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if (target_var_->Max() == RootMin() && target_var_->Max() != kint64max) {
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// We can fix all terms to min.
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for (int i = 0; i < size_; ++i) {
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vars_[i]->SetValue(vars_[i]->Min());
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}
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} else if (target_var_->Min() == RootMax() &&
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target_var_->Min() != kint64min) {
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// We can fix all terms to max.
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for (int i = 0; i < size_; ++i) {
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vars_[i]->SetValue(vars_[i]->Max());
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}
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} else {
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PushDown(0, 0, target_var_->Min(), target_var_->Max());
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}
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}
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void PushDown(int depth, int position, int64 new_min, int64 new_max) {
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// Nothing to do?
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if (new_min <= Min(depth, position) && new_max >= Max(depth, position)) {
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return;
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}
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// Leaf node -> push to leaf var.
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if (IsLeaf(depth)) {
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vars_[position]->SetRange(new_min, new_max);
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return;
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}
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// Standard propagation from the bounds of the sum to the
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// individuals terms.
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// These are maintained automatically in the tree structure.
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const int64 sum_min = Min(depth, position);
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const int64 sum_max = Max(depth, position);
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// Intersect the new bounds with the computed bounds.
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new_max = std::min(sum_max, new_max);
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new_min = std::max(sum_min, new_min);
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// Detect failure early.
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if (new_max < sum_min || new_min > sum_max) {
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solver()->Fail();
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}
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// Push to children nodes.
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const int block_start = ChildStart(position);
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const int block_end = ChildEnd(depth, position);
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for (int i = block_start; i <= block_end; ++i) {
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const int64 target_var_min = Min(depth + 1, i);
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const int64 target_var_max = Max(depth + 1, i);
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const int64 residual_min = sum_min - target_var_min;
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const int64 residual_max = sum_max - target_var_max;
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PushDown(depth + 1, i, new_min - residual_max, new_max - residual_min);
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}
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// TODO(user) : Is the diameter optimization (see reference
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// above, rule 5) useful?
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}
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void LeafChanged(int term_index) {
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IntVar* const var = vars_[term_index];
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PushUp(term_index, var->Min() - var->OldMin(), var->OldMax() - var->Max());
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Enqueue(sum_demon_); // TODO(user): Is this needed?
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}
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void PushUp(int position, int64 delta_min, int64 delta_max) {
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DCHECK_GE(delta_max, 0);
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DCHECK_GE(delta_min, 0);
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DCHECK_GT(delta_min + delta_max, 0);
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for (int depth = MaxDepth(); depth >= 0; --depth) {
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ReduceRange(depth, position, delta_min, delta_max);
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position = Parent(position);
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}
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DCHECK_EQ(0, position);
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target_var_->SetRange(RootMin(), RootMax());
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}
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string DebugString() const {
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return DebugStringInternal("Sum");
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}
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virtual void Accept(ModelVisitor* const visitor) const {
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AcceptInternal(ModelVisitor::kSumEqual, visitor);
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}
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private:
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Demon* sum_demon_;
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};
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// ----- SafeSumConstraint -----
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bool DetectSumOverflow(const std::vector<IntVar*>& vars) {
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int64 sum_min = 0;
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int64 sum_max = 0;
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for (int i = 0; i < vars.size(); ++i) {
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sum_min = CapAdd(sum_min, vars[i]->Min());
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sum_max = CapAdd(sum_max, vars[i]->Max());
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if (sum_min == kint64min || sum_max == kint64max) {
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return true;
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}
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}
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return false;
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}
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// This constraint implements sum(vars) == sum_var.
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class SafeSumConstraint : public TreeArrayConstraint {
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public:
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SafeSumConstraint(Solver* const solver,
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const std::vector<IntVar*>& vars,
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IntVar* const sum_var)
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: TreeArrayConstraint(solver, vars, sum_var), sum_demon_(NULL) {}
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virtual ~SafeSumConstraint() {}
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virtual void Post() {
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for (int i = 0; i < size_; ++i) {
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Demon* const demon = MakeConstraintDemon1(solver(),
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this,
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&SafeSumConstraint::LeafChanged,
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"LeafChanged",
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i);
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vars_[i]->WhenRange(demon);
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}
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sum_demon_ = solver()->RegisterDemon(
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MakeDelayedConstraintDemon0(solver(),
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this,
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&SafeSumConstraint::SumChanged,
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"SumChanged"));
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target_var_->WhenRange(sum_demon_);
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}
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void SafeComputeNode(int depth,
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int position,
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int64* const sum_min,
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int64* const sum_max) {
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DCHECK_LT(depth, MaxDepth());
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const int block_start = ChildStart(position);
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const int block_end = ChildEnd(depth, position);
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for (int k = block_start; k <= block_end; ++k) {
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if (*sum_min != kint64min) {
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*sum_min = CapAdd(*sum_min, Min(depth + 1, k));
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}
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if (*sum_max != kint64max) {
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*sum_max = CapAdd(*sum_max, Max(depth + 1, k));
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}
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if (*sum_min == kint64min && *sum_max == kint64max) {
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break;
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}
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}
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}
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virtual void InitialPropagate() {
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// Copy vars to leaf nodes.
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for (int i = 0; i < size_; ++i) {
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InitLeaf(i, vars_[i]->Min(), vars_[i]->Max());
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}
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// Compute up.
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for (int i = MaxDepth() - 1; i >= 0; --i) {
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for (int j = 0; j < Width(i); ++j) {
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int64 sum_min = 0;
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int64 sum_max = 0;
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SafeComputeNode(i, j, &sum_min, &sum_max);
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InitNode(i, j, sum_min, sum_max);
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}
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}
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// Propagate to sum_var.
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target_var_->SetRange(RootMin(), RootMax());
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// Push down.
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SumChanged();
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}
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void SumChanged() {
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if (target_var_->Max() == RootMin()) {
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// We can fix all terms to min.
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for (int i = 0; i < size_; ++i) {
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vars_[i]->SetValue(vars_[i]->Min());
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}
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} else if (target_var_->Min() == RootMax()) {
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// We can fix all terms to max.
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for (int i = 0; i < size_; ++i) {
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vars_[i]->SetValue(vars_[i]->Max());
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}
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} else {
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PushDown(0, 0, target_var_->Min(), target_var_->Max());
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}
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}
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void PushDown(int depth, int position, int64 new_min, int64 new_max) {
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// Nothing to do?
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if (new_min <= Min(depth, position) && new_max >= Max(depth, position)) {
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return;
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}
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// Leaf node -> push to leaf var.
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if (IsLeaf(depth)) {
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vars_[position]->SetRange(new_min, new_max);
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return;
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}
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// Standard propagation from the bounds of the sum to the
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// individuals terms.
|
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// These are maintained automatically in the tree structure.
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const int64 sum_min = Min(depth, position);
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const int64 sum_max = Max(depth, position);
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// Intersect the new bounds with the computed bounds.
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new_max = std::min(sum_max, new_max);
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new_min = std::max(sum_min, new_min);
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// Detect failure early.
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if (new_max < sum_min || new_min > sum_max) {
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solver()->Fail();
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}
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// Push to children nodes.
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const int block_start = ChildStart(position);
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const int block_end = ChildEnd(depth, position);
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for (int pos = block_start; pos <= block_end; ++pos) {
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const int64 target_var_min = Min(depth + 1, pos);
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const int64 residual_min = sum_min != kint64min ?
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CapSub(sum_min, target_var_min) :
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kint64min;
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const int64 target_var_max = Max(depth + 1, pos);
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const int64 residual_max = sum_max != kint64max ?
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CapSub(sum_max, target_var_max) :
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kint64max;
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PushDown(depth + 1,
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pos,
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(residual_max == kint64min ?
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kint64min :
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CapSub(new_min, residual_max)),
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(residual_min == kint64max ?
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kint64min :
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CapSub(new_max, residual_min)));
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}
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// TODO(user) : Is the diameter optimization (see reference
|
||
// above, rule 5) useful?
|
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}
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void LeafChanged(int term_index) {
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IntVar* const var = vars_[term_index];
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PushUp(term_index,
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CapSub(var->Min(), var->OldMin()),
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CapSub(var->OldMax(), var->Max()));
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Enqueue(sum_demon_); // TODO(user): Is this needed?
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}
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void PushUp(int position, int64 delta_min, int64 delta_max) {
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DCHECK_GE(delta_max, 0);
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DCHECK_GE(delta_min, 0);
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DCHECK_GT(CapAdd(delta_min, delta_max), 0);
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bool delta_corrupted = false;
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for (int depth = MaxDepth(); depth >= 0; --depth) {
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if (Min(depth, position) != kint64min &&
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Max(depth, position) != kint64max &&
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!delta_corrupted) { // No overflow.
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ReduceRange(depth, position, delta_min, delta_max);
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} else if (depth == MaxDepth()) { // Leaf.
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SetRange(depth,
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position,
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vars_[position]->Min(),
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vars_[position]->Max());
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delta_corrupted = true;
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} else { // Recompute.
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int64 sum_min = 0;
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int64 sum_max = 0;
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SafeComputeNode(depth, position, &sum_min, &sum_max);
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if (sum_min == kint64min && sum_max == kint64max) {
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return; // Nothing to do upward.
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}
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SetRange(depth, position, sum_min, sum_max);
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delta_corrupted = true;
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}
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position = Parent(position);
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}
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DCHECK_EQ(0, position);
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target_var_->SetRange(RootMin(), RootMax());
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||
}
|
||
|
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string DebugString() const {
|
||
return DebugStringInternal("Sum");
|
||
}
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
AcceptInternal(ModelVisitor::kSumEqual, visitor);
|
||
}
|
||
|
||
private:
|
||
Demon* sum_demon_;
|
||
};
|
||
|
||
// ---------- Min Array ----------
|
||
|
||
// This constraint implements min(vars) == min_var.
|
||
class MinConstraint : public TreeArrayConstraint {
|
||
public:
|
||
MinConstraint(Solver* const solver,
|
||
const std::vector<IntVar*>& vars,
|
||
IntVar* const min_var)
|
||
: TreeArrayConstraint(solver, vars, min_var), min_demon_(NULL) {}
|
||
|
||
virtual ~MinConstraint() {}
|
||
|
||
virtual void Post() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
Demon* const demon = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&MinConstraint::LeafChanged,
|
||
"LeafChanged",
|
||
i);
|
||
vars_[i]->WhenRange(demon);
|
||
}
|
||
min_demon_ = solver()->RegisterDemon(
|
||
MakeDelayedConstraintDemon0(solver(),
|
||
this,
|
||
&MinConstraint::MinVarChanged,
|
||
"MinVarChanged"));
|
||
target_var_->WhenRange(min_demon_);
|
||
}
|
||
|
||
virtual void InitialPropagate() {
|
||
// Copy vars to leaf nodes.
|
||
for (int i = 0; i < size_; ++i) {
|
||
InitLeaf(i, vars_[i]->Min(), vars_[i]->Max());
|
||
}
|
||
|
||
// Compute up.
|
||
for (int i = MaxDepth() - 1; i >= 0; --i) {
|
||
for (int j = 0; j < Width(i); ++j) {
|
||
int64 min_min = kint64max;
|
||
int64 min_max = kint64max;
|
||
const int block_start = ChildStart(j);
|
||
const int block_end = ChildEnd(i, j);
|
||
for (int k = block_start; k <= block_end; ++k) {
|
||
min_min = std::min(min_min, Min(i + 1, k));
|
||
min_max = std::min(min_max, Max(i + 1, k));
|
||
}
|
||
InitNode(i, j, min_min, min_max);
|
||
}
|
||
}
|
||
// Propagate to min_var.
|
||
target_var_->SetRange(RootMin(), RootMax());
|
||
|
||
// Push down.
|
||
MinVarChanged();
|
||
}
|
||
|
||
void MinVarChanged() {
|
||
PushDown(0, 0, target_var_->Min(), target_var_->Max());
|
||
}
|
||
|
||
void PushDown(int depth, int position, int64 new_min, int64 new_max) {
|
||
// Nothing to do?
|
||
if (new_min <= Min(depth, position) && new_max >= Max(depth, position)) {
|
||
return;
|
||
}
|
||
|
||
// Leaf node -> push to leaf var.
|
||
if (IsLeaf(depth)) {
|
||
vars_[position]->SetRange(new_min, new_max);
|
||
return;
|
||
}
|
||
|
||
const int64 node_min = Min(depth, position);
|
||
const int64 node_max = Max(depth, position);
|
||
|
||
int candidate = -1;
|
||
int active = 0;
|
||
const int block_start = ChildStart(position);
|
||
const int block_end = ChildEnd(depth, position);
|
||
|
||
if (new_max < node_max) {
|
||
// Look if only one candidat to push the max down.
|
||
for (int i = block_start; i <= block_end; ++i) {
|
||
if (Min(depth + 1, i) <= new_max) {
|
||
if (active++ >= 1) {
|
||
break;
|
||
}
|
||
candidate = i;
|
||
}
|
||
}
|
||
if (active == 0) {
|
||
solver()->Fail();
|
||
}
|
||
}
|
||
|
||
if (node_min < new_min) {
|
||
for (int i = block_start; i <= block_end; ++i) {
|
||
if (i == candidate && active == 1) {
|
||
PushDown(depth + 1, i, new_min, new_max);
|
||
} else {
|
||
PushDown(depth + 1, i, new_min, Max(depth + 1, i));
|
||
}
|
||
}
|
||
} else if (active == 1) {
|
||
PushDown(depth + 1, candidate, Min(depth + 1, candidate), new_max);
|
||
}
|
||
}
|
||
|
||
void LeafChanged(int term_index) {
|
||
IntVar* const var = vars_[term_index];
|
||
SetRange(MaxDepth(), term_index, var->Min(), var->Max());
|
||
PushUp(term_index);
|
||
}
|
||
|
||
void PushUp(int position) {
|
||
int depth = MaxDepth();
|
||
while (depth > 0) {
|
||
const int parent = Parent(position);
|
||
const int parent_depth = depth - 1;
|
||
int64 min_min = kint64max;
|
||
int64 min_max = kint64max;
|
||
const int block_start = ChildStart(parent);
|
||
const int block_end = ChildEnd(parent_depth, parent);
|
||
for (int k = block_start; k <= block_end; ++k) {
|
||
min_min = std::min(min_min, Min(depth, k));
|
||
min_max = std::min(min_max, Max(depth, k));
|
||
}
|
||
if (min_min > Min(parent_depth, parent) ||
|
||
min_max < Max(parent_depth, parent)) {
|
||
SetRange(parent_depth, parent, min_min, min_max);
|
||
} else {
|
||
break;
|
||
}
|
||
depth = parent_depth;
|
||
position = parent;
|
||
}
|
||
if (depth == 0) { // We have pushed all the way up.
|
||
target_var_->SetRange(RootMin(), RootMax());
|
||
}
|
||
MinVarChanged();
|
||
}
|
||
|
||
string DebugString() const {
|
||
return DebugStringInternal("Min");
|
||
}
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
AcceptInternal(ModelVisitor::kMinEqual, visitor);
|
||
}
|
||
|
||
private:
|
||
Demon* min_demon_;
|
||
};
|
||
|
||
// ---------- Max Array ----------
|
||
|
||
// This constraint implements max(vars) == max_var.
|
||
class MaxConstraint : public TreeArrayConstraint {
|
||
public:
|
||
MaxConstraint(Solver* const solver,
|
||
const std::vector<IntVar*>& vars,
|
||
IntVar* const max_var)
|
||
: TreeArrayConstraint(solver, vars, max_var), max_demon_(NULL) {}
|
||
|
||
virtual ~MaxConstraint() {}
|
||
|
||
virtual void Post() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
Demon* const demon = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&MaxConstraint::LeafChanged,
|
||
"LeafChanged",
|
||
i);
|
||
vars_[i]->WhenRange(demon);
|
||
}
|
||
max_demon_ = solver()->RegisterDemon(
|
||
MakeDelayedConstraintDemon0(solver(),
|
||
this,
|
||
&MaxConstraint::MaxVarChanged,
|
||
"MaxVarChanged"));
|
||
target_var_->WhenRange(max_demon_);
|
||
}
|
||
|
||
virtual void InitialPropagate() {
|
||
// Copy vars to leaf nodes.
|
||
for (int i = 0; i < size_; ++i) {
|
||
InitLeaf(i, vars_[i]->Min(), vars_[i]->Max());
|
||
}
|
||
|
||
// Compute up.
|
||
for (int i = MaxDepth() - 1; i >= 0; --i) {
|
||
for (int j = 0; j < Width(i); ++j) {
|
||
int64 max_min = kint64min;
|
||
int64 max_max = kint64min;
|
||
const int block_start = ChildStart(j);
|
||
const int block_end = ChildEnd(i, j);
|
||
for (int k = block_start; k <= block_end; ++k) {
|
||
max_min = std::max(max_min, Min(i + 1, k));
|
||
max_max = std::max(max_max, Max(i + 1, k));
|
||
}
|
||
InitNode(i, j, max_min, max_max);
|
||
}
|
||
}
|
||
// Propagate to min_var.
|
||
target_var_->SetRange(RootMin(), RootMax());
|
||
|
||
// Push down.
|
||
MaxVarChanged();
|
||
}
|
||
|
||
void MaxVarChanged() {
|
||
PushDown(0, 0, target_var_->Min(), target_var_->Max());
|
||
}
|
||
|
||
void PushDown(int depth, int position, int64 new_min, int64 new_max) {
|
||
// Nothing to do?
|
||
if (new_min <= Min(depth, position) && new_max >= Max(depth, position)) {
|
||
return;
|
||
}
|
||
|
||
// Leaf node -> push to leaf var.
|
||
if (IsLeaf(depth)) {
|
||
vars_[position]->SetRange(new_min, new_max);
|
||
return;
|
||
}
|
||
|
||
const int64 node_min = Min(depth, position);
|
||
const int64 node_max = Max(depth, position);
|
||
|
||
int candidate = -1;
|
||
int active = 0;
|
||
const int block_start = ChildStart(position);
|
||
const int block_end = ChildEnd(depth, position);
|
||
|
||
if (node_min < new_min) {
|
||
// Look if only one candidat to push the max down.
|
||
for (int i = block_start; i <= block_end; ++i) {
|
||
if (Max(depth + 1, i) >= new_min) {
|
||
if (active++ >= 1) {
|
||
break;
|
||
}
|
||
candidate = i;
|
||
}
|
||
}
|
||
if (active == 0) {
|
||
solver()->Fail();
|
||
}
|
||
}
|
||
|
||
if (node_max > new_max) {
|
||
for (int i = block_start; i <= block_end; ++i) {
|
||
if (i == candidate && active == 1) {
|
||
PushDown(depth + 1, i, new_min, new_max);
|
||
} else {
|
||
PushDown(depth + 1, i, Min(depth + 1, i), new_max);
|
||
}
|
||
}
|
||
} else if (active == 1) {
|
||
PushDown(depth + 1, candidate, new_min, Max(depth + 1, candidate));
|
||
}
|
||
}
|
||
|
||
void LeafChanged(int term_index) {
|
||
IntVar* const var = vars_[term_index];
|
||
SetRange(MaxDepth(), term_index, var->Min(), var->Max());
|
||
PushUp(term_index);
|
||
}
|
||
|
||
void PushUp(int position) {
|
||
int depth = MaxDepth();
|
||
while (depth > 0) {
|
||
const int parent = Parent(position);
|
||
const int parent_depth = depth - 1;
|
||
int64 max_min = kint64min;
|
||
int64 max_max = kint64min;
|
||
const int block_start = ChildStart(parent);
|
||
const int block_end = ChildEnd(parent_depth, parent);
|
||
for (int k = block_start; k <= block_end; ++k) {
|
||
max_min = std::max(max_min, Min(depth, k));
|
||
max_max = std::max(max_max, Max(depth, k));
|
||
}
|
||
if (max_min > Min(parent_depth, parent) ||
|
||
max_max < Max(parent_depth, parent)) {
|
||
SetRange(parent_depth, parent, max_min, max_max);
|
||
} else {
|
||
break;
|
||
}
|
||
depth = parent_depth;
|
||
position = parent;
|
||
}
|
||
if (depth == 0) { // We have pushed all the way up.
|
||
target_var_->SetRange(RootMin(), RootMax());
|
||
}
|
||
MaxVarChanged();
|
||
}
|
||
|
||
string DebugString() const {
|
||
return DebugStringInternal("Max");
|
||
}
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
AcceptInternal(ModelVisitor::kMaxEqual, visitor);
|
||
}
|
||
|
||
private:
|
||
Demon* max_demon_;
|
||
};
|
||
|
||
// Boolean And and Ors
|
||
|
||
class ArrayBoolAndEq : public CastConstraint {
|
||
public:
|
||
ArrayBoolAndEq(Solver* const s,
|
||
const std::vector<IntVar*>& vars,
|
||
IntVar* const target)
|
||
: CastConstraint(s, target),
|
||
vars_(vars),
|
||
demons_(vars.size()),
|
||
unbounded_(0) {}
|
||
|
||
virtual ~ArrayBoolAndEq() {}
|
||
|
||
virtual void Post() {
|
||
for (int i = 0; i < vars_.size(); ++i) {
|
||
if (!vars_[i]->Bound()) {
|
||
demons_[i] = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&ArrayBoolAndEq::PropagateVar,
|
||
"PropagateVar",
|
||
i);
|
||
vars_[i]->WhenBound(demons_[i]);
|
||
}
|
||
|
||
}
|
||
Demon* const target_demon =
|
||
MakeConstraintDemon0(solver(),
|
||
this,
|
||
&ArrayBoolAndEq::PropagateTarget,
|
||
"PropagateTarget");
|
||
target_var_->WhenBound(target_demon);
|
||
}
|
||
|
||
virtual void InitialPropagate() {
|
||
target_var_->SetRange(0, 1);
|
||
if (target_var_->Min() == 1) {
|
||
for (int i = 0; i < vars_.size(); ++i) {
|
||
vars_[i]->SetMin(1);
|
||
}
|
||
} else {
|
||
int zeros = 0;
|
||
int ones = 0;
|
||
int unbounded = 0;
|
||
for (int i = 0; i < vars_.size(); ++i) {
|
||
unbounded += !vars_[i]->Bound();
|
||
zeros += vars_[i]->Max() == 0;
|
||
ones += vars_[i]->Min() == 1;
|
||
}
|
||
if (zeros > 0) {
|
||
InhibitAll();
|
||
target_var_->SetMax(0);
|
||
} else if (unbounded == 0) {
|
||
target_var_->SetMin(1);
|
||
} else if (target_var_->Max() == 0 && unbounded == 1) {
|
||
const int index = FindPossibleZero();
|
||
CHECK(index != -1);
|
||
vars_[index]->SetMax(0);
|
||
} else {
|
||
unbounded_.SetValue(solver(), unbounded);
|
||
}
|
||
}
|
||
}
|
||
|
||
void PropagateVar(int index) {
|
||
if (vars_[index]->Min() == 1) {
|
||
unbounded_.Decr(solver());
|
||
if (unbounded_.Value() == 0 && !decided_.Switched()) {
|
||
target_var_->SetMin(1);
|
||
decided_.Switch(solver());
|
||
}
|
||
if (target_var_->Max() == 0 &&
|
||
unbounded_.Value() == 1 &&
|
||
!decided_.Switched()) {
|
||
const int to_set = FindPossibleZero();
|
||
if (to_set != -1) {
|
||
vars_[to_set]->SetMax(0);
|
||
decided_.Switch(solver());
|
||
} else {
|
||
solver()->Fail();
|
||
}
|
||
}
|
||
} else {
|
||
InhibitAll();
|
||
target_var_->SetMax(0);
|
||
}
|
||
}
|
||
|
||
void PropagateTarget() {
|
||
if (target_var_->Min() == 1) {
|
||
for (int i = 0; i < vars_.size(); ++i) {
|
||
vars_[i]->SetMin(1);
|
||
}
|
||
} else {
|
||
if (unbounded_.Value() == 1 && !decided_.Switched()) {
|
||
const int to_set = FindPossibleZero();
|
||
if (to_set != -1) {
|
||
vars_[to_set]->SetMax(0);
|
||
decided_.Switch(solver());
|
||
} else {
|
||
solver()->Fail();
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
void InhibitAll() {
|
||
for (int i = 0; i < demons_.size(); ++i) {
|
||
if (demons_[i] != NULL) {
|
||
demons_[i]->inhibit(solver());
|
||
}
|
||
}
|
||
}
|
||
|
||
int FindPossibleZero() {
|
||
for (int i = 0; i < vars_.size(); ++i) {
|
||
if (vars_[i]->Min() == 0) {
|
||
return i;
|
||
}
|
||
}
|
||
return -1;
|
||
}
|
||
|
||
string DebugString() const {
|
||
return StringPrintf("And(%s) == %s",
|
||
DebugStringVector(vars_, ", ").c_str(),
|
||
target_var_->DebugString().c_str());
|
||
}
|
||
|
||
void Accept(ModelVisitor* const visitor) const {
|
||
visitor->BeginVisitConstraint(ModelVisitor::kMinEqual, this);
|
||
visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
|
||
vars_.data(), vars_.size());
|
||
visitor->VisitIntegerExpressionArgument(ModelVisitor::kTargetArgument,
|
||
target_var_);
|
||
visitor->EndVisitConstraint(ModelVisitor::kMinEqual, this);
|
||
}
|
||
|
||
private:
|
||
std::vector<IntVar*> vars_;
|
||
std::vector<Demon*> demons_;
|
||
NumericalRev<int> unbounded_;
|
||
RevSwitch decided_;
|
||
};
|
||
|
||
class ArrayBoolOrEq : public CastConstraint {
|
||
public:
|
||
ArrayBoolOrEq(Solver* const s,
|
||
const std::vector<IntVar*>& vars,
|
||
IntVar* const target)
|
||
: CastConstraint(s, target),
|
||
vars_(vars),
|
||
demons_(vars.size()),
|
||
unbounded_(0) {}
|
||
|
||
virtual ~ArrayBoolOrEq() {}
|
||
|
||
virtual void Post() {
|
||
for (int i = 0; i < vars_.size(); ++i) {
|
||
if (!vars_[i]->Bound()) {
|
||
demons_[i] = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&ArrayBoolOrEq::PropagateVar,
|
||
"PropagateVar",
|
||
i);
|
||
vars_[i]->WhenBound(demons_[i]);
|
||
}
|
||
|
||
}
|
||
Demon* const target_demon =
|
||
MakeConstraintDemon0(solver(),
|
||
this,
|
||
&ArrayBoolOrEq::PropagateTarget,
|
||
"PropagateTarget");
|
||
target_var_->WhenBound(target_demon);
|
||
}
|
||
|
||
virtual void InitialPropagate() {
|
||
target_var_->SetRange(0, 1);
|
||
if (target_var_->Max() == 0) {
|
||
for (int i = 0; i < vars_.size(); ++i) {
|
||
vars_[i]->SetMax(0);
|
||
}
|
||
} else {
|
||
int zeros = 0;
|
||
int ones = 0;
|
||
int unbounded = 0;
|
||
for (int i = 0; i < vars_.size(); ++i) {
|
||
unbounded += !vars_[i]->Bound();
|
||
zeros += vars_[i]->Max() == 0;
|
||
ones += vars_[i]->Min() == 1;
|
||
}
|
||
if (ones > 0) {
|
||
InhibitAll();
|
||
target_var_->SetMin(1);
|
||
} else if (unbounded == 0) {
|
||
target_var_->SetMax(0);
|
||
} else if (target_var_->Min() == 1 && unbounded == 1) {
|
||
const int index = FindPossibleOne();
|
||
CHECK(index != -1);
|
||
vars_[index]->SetMin(1);
|
||
} else {
|
||
unbounded_.SetValue(solver(), unbounded);
|
||
}
|
||
}
|
||
}
|
||
|
||
void PropagateVar(int index) {
|
||
if (vars_[index]->Min() == 0) {
|
||
unbounded_.Decr(solver());
|
||
if (unbounded_.Value() == 0 && !decided_.Switched()) {
|
||
target_var_->SetMax(0);
|
||
decided_.Switch(solver());
|
||
}
|
||
if (target_var_->Min() == 1 &&
|
||
unbounded_.Value() == 1 &&
|
||
!decided_.Switched()) {
|
||
const int to_set = FindPossibleOne();
|
||
if (to_set != -1) {
|
||
vars_[to_set]->SetMin(1);
|
||
decided_.Switch(solver());
|
||
} else {
|
||
solver()->Fail();
|
||
}
|
||
}
|
||
} else {
|
||
InhibitAll();
|
||
target_var_->SetMin(1);
|
||
}
|
||
}
|
||
|
||
void PropagateTarget() {
|
||
if (target_var_->Max() == 0) {
|
||
for (int i = 0; i < vars_.size(); ++i) {
|
||
vars_[i]->SetMax(0);
|
||
}
|
||
} else {
|
||
if (unbounded_.Value() == 1 && !decided_.Switched()) {
|
||
const int to_set = FindPossibleOne();
|
||
if (to_set != -1) {
|
||
vars_[to_set]->SetMin(1);
|
||
decided_.Switch(solver());
|
||
} else {
|
||
solver()->Fail();
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
void InhibitAll() {
|
||
for (int i = 0; i < demons_.size(); ++i) {
|
||
if (demons_[i] != NULL) {
|
||
demons_[i]->inhibit(solver());
|
||
}
|
||
}
|
||
}
|
||
|
||
int FindPossibleOne() {
|
||
for (int i = 0; i < vars_.size(); ++i) {
|
||
if (vars_[i]->Max() == 1) {
|
||
return i;
|
||
}
|
||
}
|
||
return -1;
|
||
}
|
||
|
||
string DebugString() const {
|
||
return StringPrintf("Or(%s) == %s",
|
||
DebugStringVector(vars_, ", ").c_str(),
|
||
target_var_->DebugString().c_str());
|
||
}
|
||
|
||
void Accept(ModelVisitor* const visitor) const {
|
||
visitor->BeginVisitConstraint(ModelVisitor::kMaxEqual, this);
|
||
visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
|
||
vars_.data(), vars_.size());
|
||
visitor->VisitIntegerExpressionArgument(ModelVisitor::kTargetArgument,
|
||
target_var_);
|
||
visitor->EndVisitConstraint(ModelVisitor::kMaxEqual, this);
|
||
}
|
||
|
||
private:
|
||
std::vector<IntVar*> vars_;
|
||
std::vector<Demon*> demons_;
|
||
NumericalRev<int> unbounded_;
|
||
RevSwitch decided_;
|
||
};
|
||
|
||
// ---------- Specialized cases ----------
|
||
|
||
bool AreAllBooleans(const IntVar* const* vars, int size) {
|
||
for (int i = 0; i < size; ++i) {
|
||
const IntVar* var = vars[i];
|
||
if (var->Min() < 0 || var->Max() > 1) {
|
||
return false;
|
||
}
|
||
}
|
||
return true;
|
||
}
|
||
|
||
template<class T> bool AreAllPositive(const T* const values, int size) {
|
||
for (int i = 0; i < size; ++i) {
|
||
if (values[i] < 0) {
|
||
return false;
|
||
}
|
||
}
|
||
return true;
|
||
}
|
||
|
||
template<class T> bool AreAllStrictlyPositive(const T* const values, int size) {
|
||
for (int i = 0; i < size; ++i) {
|
||
if (values[i] <= 0) {
|
||
return false;
|
||
}
|
||
}
|
||
return true;
|
||
}
|
||
|
||
|
||
template<class T> bool AreAllNull(const T* const values, int size) {
|
||
for (int i = 0; i < size; ++i) {
|
||
if (values[i] != 0) {
|
||
return false;
|
||
}
|
||
}
|
||
return true;
|
||
}
|
||
|
||
template<class T> bool AreAllOnes(const T* const values, int size) {
|
||
for (int i = 0; i < size; ++i) {
|
||
if (values[i] != 1) {
|
||
return false;
|
||
}
|
||
}
|
||
return true;
|
||
}
|
||
|
||
template <class T> bool AreAllBoundOrNull(const IntVar* const * vars,
|
||
const T* const values,
|
||
int size) {
|
||
for (int i = 0; i < size; ++i) {
|
||
if (values[i] != 0 && !vars[i]->Bound()) {
|
||
return false;
|
||
}
|
||
}
|
||
return true;
|
||
}
|
||
|
||
class BaseSumBooleanConstraint : public Constraint {
|
||
public:
|
||
BaseSumBooleanConstraint(Solver* const s,
|
||
const IntVar* const* vars,
|
||
int size)
|
||
: Constraint(s), vars_(new IntVar*[size]), size_(size) {
|
||
CHECK_GT(size_, 0);
|
||
CHECK(vars != NULL);
|
||
memcpy(vars_.get(), vars, size_ * sizeof(*vars));
|
||
}
|
||
virtual ~BaseSumBooleanConstraint() {}
|
||
|
||
protected:
|
||
string DebugStringInternal(const string& name) const;
|
||
|
||
const scoped_array<IntVar*> vars_;
|
||
const int size_;
|
||
RevSwitch inactive_;
|
||
};
|
||
|
||
string BaseSumBooleanConstraint::DebugStringInternal(const string& name) const {
|
||
string out = name + "(";
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (i > 0) {
|
||
out += ", ";
|
||
}
|
||
out += vars_[i]->DebugString();
|
||
}
|
||
out += ")";
|
||
return out;
|
||
}
|
||
|
||
// ----- Sum of Boolean <= 1 -----
|
||
|
||
class SumBooleanLessOrEqualToOne : public BaseSumBooleanConstraint {
|
||
public:
|
||
SumBooleanLessOrEqualToOne(Solver* const s,
|
||
const IntVar* const* vars,
|
||
int size)
|
||
: BaseSumBooleanConstraint(s, vars, size) {}
|
||
|
||
virtual ~SumBooleanLessOrEqualToOne() {}
|
||
|
||
virtual void Post() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (!vars_[i]->Bound()) {
|
||
Demon* u = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&SumBooleanLessOrEqualToOne::Update,
|
||
"Update",
|
||
i);
|
||
vars_[i]->WhenBound(u);
|
||
}
|
||
}
|
||
}
|
||
|
||
virtual void InitialPropagate() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Min() == 1) {
|
||
PushAllToZeroExcept(i);
|
||
return;
|
||
}
|
||
}
|
||
}
|
||
|
||
void Update(int index) {
|
||
if (!inactive_.Switched()) {
|
||
DCHECK(vars_[index]->Bound());
|
||
if (vars_[index]->Min() == 1) {
|
||
PushAllToZeroExcept(index);
|
||
}
|
||
}
|
||
}
|
||
|
||
void PushAllToZeroExcept(int index) {
|
||
inactive_.Switch(solver());
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (i != index && vars_[i]->Max() != 0) {
|
||
vars_[i]->SetMax(0);
|
||
}
|
||
}
|
||
}
|
||
|
||
virtual string DebugString() const {
|
||
return DebugStringInternal("SumBooleanLessOrEqualToOne");
|
||
}
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
visitor->BeginVisitConstraint(ModelVisitor::kSumLessOrEqual, this);
|
||
visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
|
||
vars_.get(),
|
||
size_);
|
||
visitor->VisitIntegerArgument(ModelVisitor::kValueArgument, 1);
|
||
visitor->EndVisitConstraint(ModelVisitor::kSumLessOrEqual, this);
|
||
}
|
||
};
|
||
|
||
// ----- Sum of Boolean >= 1 -----
|
||
|
||
// We implement this one as a Max(array) == 1.
|
||
|
||
class SumBooleanGreaterOrEqualToOne : public BaseSumBooleanConstraint {
|
||
public:
|
||
SumBooleanGreaterOrEqualToOne(Solver* const s, const IntVar* const * vars,
|
||
int size);
|
||
virtual ~SumBooleanGreaterOrEqualToOne() {}
|
||
|
||
virtual void Post();
|
||
virtual void InitialPropagate();
|
||
|
||
void Update(int index);
|
||
void UpdateVar();
|
||
|
||
virtual string DebugString() const;
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
visitor->BeginVisitConstraint(ModelVisitor::kSumGreaterOrEqual, this);
|
||
visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
|
||
vars_.get(),
|
||
size_);
|
||
visitor->VisitIntegerArgument(ModelVisitor::kValueArgument, 1);
|
||
visitor->EndVisitConstraint(ModelVisitor::kSumGreaterOrEqual, this);
|
||
}
|
||
|
||
private:
|
||
RevBitSet bits_;
|
||
};
|
||
|
||
SumBooleanGreaterOrEqualToOne::SumBooleanGreaterOrEqualToOne(
|
||
Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size)
|
||
: BaseSumBooleanConstraint(s, vars, size), bits_(size) {}
|
||
|
||
void SumBooleanGreaterOrEqualToOne::Post() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
Demon* d = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&SumBooleanGreaterOrEqualToOne::Update,
|
||
"Update",
|
||
i);
|
||
vars_[i]->WhenRange(d);
|
||
}
|
||
}
|
||
|
||
void SumBooleanGreaterOrEqualToOne::InitialPropagate() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
IntVar* const var = vars_[i];
|
||
if (var->Min() == 1LL) {
|
||
inactive_.Switch(solver());
|
||
return;
|
||
}
|
||
if (var->Max() == 1LL) {
|
||
bits_.SetToOne(solver(), i);
|
||
}
|
||
}
|
||
if (bits_.IsCardinalityZero()) {
|
||
solver()->Fail();
|
||
} else if (bits_.IsCardinalityOne()) {
|
||
vars_[bits_.GetFirstBit(0)]->SetValue(1LL);
|
||
inactive_.Switch(solver());
|
||
}
|
||
}
|
||
|
||
void SumBooleanGreaterOrEqualToOne::Update(int index) {
|
||
if (!inactive_.Switched()) {
|
||
if (vars_[index]->Min() == 1LL) { // Bound to 1.
|
||
inactive_.Switch(solver());
|
||
} else {
|
||
bits_.SetToZero(solver(), index);
|
||
if (bits_.IsCardinalityZero()) {
|
||
solver()->Fail();
|
||
} else if (bits_.IsCardinalityOne()) {
|
||
vars_[bits_.GetFirstBit(0)]->SetValue(1LL);
|
||
inactive_.Switch(solver());
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
string SumBooleanGreaterOrEqualToOne::DebugString() const {
|
||
return DebugStringInternal("SumBooleanGreaterOrEqualToOne");
|
||
}
|
||
|
||
// ----- Sum of Boolean == 1 -----
|
||
|
||
class SumBooleanEqualToOne : public BaseSumBooleanConstraint {
|
||
public:
|
||
SumBooleanEqualToOne(Solver* const s,
|
||
IntVar* const* vars,
|
||
int size)
|
||
: BaseSumBooleanConstraint(s, vars, size), active_vars_(0) {}
|
||
|
||
virtual ~SumBooleanEqualToOne() {}
|
||
|
||
virtual void Post() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
Demon* u = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&SumBooleanEqualToOne::Update,
|
||
"Update",
|
||
i);
|
||
vars_[i]->WhenBound(u);
|
||
}
|
||
}
|
||
|
||
virtual void InitialPropagate() {
|
||
int min1 = 0;
|
||
int max1 = 0;
|
||
int index_min = -1;
|
||
int index_max = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
const IntVar* const var = vars_[i];
|
||
if (var->Min() == 1) {
|
||
min1++;
|
||
index_min = i;
|
||
}
|
||
if (var->Max() == 1) {
|
||
max1++;
|
||
index_max = i;
|
||
}
|
||
}
|
||
if (min1 > 1 || max1 == 0) {
|
||
solver()->Fail();
|
||
} else if (min1 == 1) {
|
||
DCHECK_NE(-1, index_min);
|
||
PushAllToZeroExcept(index_min);
|
||
} else if (max1 == 1) {
|
||
DCHECK_NE(-1, index_max);
|
||
vars_[index_max]->SetValue(1);
|
||
inactive_.Switch(solver());
|
||
} else {
|
||
active_vars_.SetValue(solver(), max1);
|
||
}
|
||
}
|
||
|
||
void Update(int index) {
|
||
if (!inactive_.Switched()) {
|
||
DCHECK(vars_[index]->Bound());
|
||
const int64 value = vars_[index]->Min(); // Faster than Value().
|
||
if (value == 0) {
|
||
active_vars_.Decr(solver());
|
||
DCHECK_GE(active_vars_.Value(), 0);
|
||
if (active_vars_.Value() == 0) {
|
||
solver()->Fail();
|
||
} else if (active_vars_.Value() == 1) {
|
||
bool found = false;
|
||
for (int i = 0; i < size_; ++i) {
|
||
IntVar* const var = vars_[i];
|
||
if (var->Max() == 1) {
|
||
var->SetValue(1);
|
||
PushAllToZeroExcept(i);
|
||
found = true;
|
||
break;
|
||
}
|
||
}
|
||
if (!found) {
|
||
solver()->Fail();
|
||
}
|
||
}
|
||
} else {
|
||
PushAllToZeroExcept(index);
|
||
}
|
||
}
|
||
}
|
||
|
||
void PushAllToZeroExcept(int index) {
|
||
inactive_.Switch(solver());
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (i != index && vars_[i]->Max() != 0) {
|
||
vars_[i]->SetMax(0);
|
||
}
|
||
}
|
||
}
|
||
|
||
virtual string DebugString() const {
|
||
return DebugStringInternal("SumBooleanEqualToOne");
|
||
}
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
visitor->BeginVisitConstraint(ModelVisitor::kSumEqual, this);
|
||
visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
|
||
vars_.get(),
|
||
size_);
|
||
visitor->VisitIntegerArgument(ModelVisitor::kValueArgument, 1);
|
||
visitor->EndVisitConstraint(ModelVisitor::kSumEqual, this);
|
||
}
|
||
|
||
private:
|
||
NumericalRev<int> active_vars_;
|
||
};
|
||
|
||
// ----- Sum of Boolean Equal To Var -----
|
||
|
||
class SumBooleanEqualToVar : public BaseSumBooleanConstraint {
|
||
public:
|
||
SumBooleanEqualToVar(Solver* const s,
|
||
IntVar* const* bool_vars,
|
||
int size,
|
||
IntVar* const sum_var)
|
||
: BaseSumBooleanConstraint(s, bool_vars, size),
|
||
num_possible_true_vars_(0),
|
||
num_always_true_vars_(0),
|
||
sum_var_(sum_var) {}
|
||
|
||
virtual ~SumBooleanEqualToVar() {}
|
||
|
||
virtual void Post() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
Demon* const u = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&SumBooleanEqualToVar::Update,
|
||
"Update",
|
||
i);
|
||
vars_[i]->WhenBound(u);
|
||
}
|
||
if (!sum_var_->Bound()) {
|
||
Demon* const u = MakeConstraintDemon0(solver(),
|
||
this,
|
||
&SumBooleanEqualToVar::UpdateVar,
|
||
"UpdateVar");
|
||
sum_var_->WhenRange(u);
|
||
}
|
||
}
|
||
|
||
virtual void InitialPropagate() {
|
||
int num_always_true_vars = 0;
|
||
int possible_true = 0;
|
||
for (int i = 0; i < size_; ++i) {
|
||
const IntVar* const var = vars_[i];
|
||
if (var->Min() == 1) {
|
||
num_always_true_vars++;
|
||
}
|
||
if (var->Max() == 1) {
|
||
possible_true++;
|
||
}
|
||
}
|
||
sum_var_->SetRange(num_always_true_vars, possible_true);
|
||
const int64 var_min = sum_var_->Min();
|
||
const int64 var_max = sum_var_->Max();
|
||
if (num_always_true_vars == var_max && possible_true > var_max) {
|
||
PushAllUnboundToZero();
|
||
} else if (possible_true == var_min && num_always_true_vars < var_min) {
|
||
PushAllUnboundToOne();
|
||
} else {
|
||
num_possible_true_vars_.SetValue(solver(), possible_true);
|
||
num_always_true_vars_.SetValue(solver(), num_always_true_vars);
|
||
}
|
||
}
|
||
|
||
void UpdateVar() {
|
||
if (!inactive_.Switched()) {
|
||
if (num_possible_true_vars_.Value() == sum_var_->Min()) {
|
||
PushAllUnboundToOne();
|
||
sum_var_->SetValue(num_possible_true_vars_.Value());
|
||
} else if (num_always_true_vars_.Value() == sum_var_->Max()) {
|
||
PushAllUnboundToZero();
|
||
sum_var_->SetValue(num_always_true_vars_.Value());
|
||
}
|
||
}
|
||
}
|
||
|
||
void Update(int index) {
|
||
if (!inactive_.Switched()) {
|
||
DCHECK(vars_[index]->Bound());
|
||
const int64 value = vars_[index]->Min(); // Faster than Value().
|
||
if (value == 0) {
|
||
num_possible_true_vars_.Decr(solver());
|
||
sum_var_->SetRange(num_always_true_vars_.Value(),
|
||
num_possible_true_vars_.Value());
|
||
if (num_possible_true_vars_.Value() == sum_var_->Min()) {
|
||
PushAllUnboundToOne();
|
||
}
|
||
} else {
|
||
DCHECK_EQ(1, value);
|
||
num_always_true_vars_.Incr(solver());
|
||
sum_var_->SetRange(num_always_true_vars_.Value(),
|
||
num_possible_true_vars_.Value());
|
||
if (num_always_true_vars_.Value() == sum_var_->Max()) {
|
||
PushAllUnboundToZero();
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
void PushAllUnboundToZero() {
|
||
int64 counter = 0;
|
||
inactive_.Switch(solver());
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Min() == 0) {
|
||
vars_[i]->SetValue(0);
|
||
} else {
|
||
counter++;
|
||
}
|
||
}
|
||
if (counter < sum_var_->Min() || counter > sum_var_->Max()) {
|
||
solver()->Fail();
|
||
}
|
||
}
|
||
|
||
void PushAllUnboundToOne() {
|
||
int64 counter = 0;
|
||
inactive_.Switch(solver());
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Max() == 1) {
|
||
vars_[i]->SetValue(1);
|
||
counter++;
|
||
}
|
||
}
|
||
if (counter < sum_var_->Min() || counter > sum_var_->Max()) {
|
||
solver()->Fail();
|
||
}
|
||
}
|
||
|
||
virtual string DebugString() const {
|
||
return StringPrintf("%s == %s",
|
||
DebugStringInternal("SumBoolean").c_str(),
|
||
sum_var_->DebugString().c_str());
|
||
}
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
visitor->BeginVisitConstraint(ModelVisitor::kSumEqual, this);
|
||
visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
|
||
vars_.get(),
|
||
size_);
|
||
visitor->VisitIntegerExpressionArgument(ModelVisitor::kTargetArgument,
|
||
sum_var_);
|
||
visitor->EndVisitConstraint(ModelVisitor::kSumEqual, this);
|
||
}
|
||
|
||
private:
|
||
NumericalRev<int> num_possible_true_vars_;
|
||
NumericalRev<int> num_always_true_vars_;
|
||
IntVar* const sum_var_;
|
||
};
|
||
|
||
// ---------- ScalProd ----------
|
||
|
||
// ----- Boolean Scal Prod -----
|
||
|
||
struct Container {
|
||
IntVar* var;
|
||
int64 coef;
|
||
Container(IntVar* v, int64 c) : var(v), coef(c) {}
|
||
bool operator<(const Container& c) const { return (coef < c.coef); }
|
||
};
|
||
|
||
// This method will sort both vars and coefficients in increasing
|
||
// coefficient order. Vars with null coefficients will be
|
||
// removed. Bound vars will be collected and the sum of the
|
||
// corresponding products (when the var is bound to 1) is returned by
|
||
// this method.
|
||
// If keep_inside is true, the constant will be added back into the
|
||
// scalprod as IntConst(1) * constant.
|
||
int64 SortBothChangeConstant(IntVar** const vars,
|
||
int64* const coefs,
|
||
int* const size,
|
||
bool keep_inside) {
|
||
CHECK_NOTNULL(vars);
|
||
CHECK_NOTNULL(coefs);
|
||
CHECK_NOTNULL(size);
|
||
if (*size == 0) {
|
||
return 0;
|
||
}
|
||
int64 cst = 0;
|
||
std::vector<Container> to_sort;
|
||
for (int index = 0; index < *size; ++index) {
|
||
if (vars[index]->Bound()) {
|
||
cst += coefs[index] * vars[index]->Min();
|
||
} else if (coefs[index] != 0) {
|
||
to_sort.push_back(Container(vars[index], coefs[index]));
|
||
}
|
||
}
|
||
if (keep_inside && cst != 0) {
|
||
CHECK_LT(to_sort.size(), *size);
|
||
Solver* const solver = vars[0]->solver();
|
||
to_sort.push_back(Container(solver->MakeIntConst(1), cst));
|
||
cst = 0;
|
||
}
|
||
std::sort(to_sort.begin(), to_sort.end());
|
||
*size = to_sort.size();
|
||
for (int index = 0; index < *size; ++index) {
|
||
vars[index] = to_sort[index].var;
|
||
coefs[index] = to_sort[index].coef;
|
||
}
|
||
return cst;
|
||
}
|
||
|
||
// This constraint implements sum(vars) == var. It is delayed such
|
||
// that propagation only occurs when all variables have been touched.
|
||
class BooleanScalProdLessConstant : public Constraint {
|
||
public:
|
||
BooleanScalProdLessConstant(Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size,
|
||
const int64* const coefs,
|
||
int64 upper_bound)
|
||
: Constraint(s),
|
||
vars_(new IntVar*[size]),
|
||
size_(size),
|
||
coefs_(new int64[size]),
|
||
upper_bound_(upper_bound),
|
||
first_unbound_backward_(size_ - 1),
|
||
sum_of_bound_variables_(0LL),
|
||
max_coefficient_(0) {
|
||
CHECK_GT(size, 0);
|
||
CHECK(vars != NULL);
|
||
CHECK(coefs != NULL);
|
||
memcpy(vars_.get(), vars, size_ * sizeof(*vars));
|
||
memcpy(coefs_.get(), coefs, size_ * sizeof(*coefs));
|
||
for (int i = 0; i < size_; ++i) {
|
||
DCHECK_GE(coefs_[i], 0);
|
||
}
|
||
upper_bound_ -= SortBothChangeConstant(vars_.get(),
|
||
coefs_.get(),
|
||
&size_,
|
||
false);
|
||
max_coefficient_.SetValue(s, coefs_[size_ - 1]);
|
||
}
|
||
|
||
BooleanScalProdLessConstant(Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size,
|
||
const int* const coefs,
|
||
int64 upper_bound)
|
||
: Constraint(s),
|
||
vars_(new IntVar*[size]),
|
||
size_(size),
|
||
coefs_(new int64[size]),
|
||
upper_bound_(upper_bound),
|
||
first_unbound_backward_(size_ - 1),
|
||
sum_of_bound_variables_(0LL),
|
||
max_coefficient_(0) {
|
||
CHECK_GT(size, 0);
|
||
CHECK(vars != NULL);
|
||
CHECK(coefs != NULL);
|
||
memcpy(vars_.get(), vars, size_ * sizeof(*vars));
|
||
for (int i = 0; i < size_; ++i) {
|
||
DCHECK_GE(coefs[i], 0);
|
||
coefs_[i] = coefs[i];
|
||
}
|
||
upper_bound_ -= SortBothChangeConstant(vars_.get(),
|
||
coefs_.get(),
|
||
&size_,
|
||
false);
|
||
max_coefficient_.SetValue(s, coefs_[size_ - 1]);
|
||
}
|
||
|
||
virtual ~BooleanScalProdLessConstant() {}
|
||
|
||
virtual void Post() {
|
||
for (int var_index = 0; var_index < size_; ++var_index) {
|
||
if (vars_[var_index]->Bound()) {
|
||
continue;
|
||
}
|
||
Demon* d = MakeConstraintDemon1(
|
||
solver(),
|
||
this,
|
||
&BooleanScalProdLessConstant::Update,
|
||
"InitialPropagate",
|
||
var_index);
|
||
vars_[var_index]->WhenRange(d);
|
||
}
|
||
}
|
||
|
||
void PushFromTop() {
|
||
const int64 slack = upper_bound_ - sum_of_bound_variables_.Value();
|
||
if (slack < 0) {
|
||
solver()->Fail();
|
||
}
|
||
if (slack < max_coefficient_.Value()) {
|
||
int64 last_unbound = first_unbound_backward_.Value();
|
||
for (; last_unbound >= 0; --last_unbound) {
|
||
if (!vars_[last_unbound]->Bound()) {
|
||
if (coefs_[last_unbound] <= slack) {
|
||
max_coefficient_.SetValue(solver(), coefs_[last_unbound]);
|
||
break;
|
||
} else {
|
||
vars_[last_unbound]->SetValue(0);
|
||
}
|
||
}
|
||
}
|
||
first_unbound_backward_.SetValue(solver(), last_unbound);
|
||
}
|
||
}
|
||
|
||
virtual void InitialPropagate() {
|
||
Solver* const s = solver();
|
||
int last_unbound = -1;
|
||
int64 sum = 0LL;
|
||
for (int index = 0; index < size_; ++index) {
|
||
if (vars_[index]->Bound()) {
|
||
const int64 value = vars_[index]->Min();
|
||
sum += value * coefs_[index];
|
||
} else {
|
||
last_unbound = index;
|
||
}
|
||
}
|
||
sum_of_bound_variables_.SetValue(s, sum);
|
||
first_unbound_backward_.SetValue(s, last_unbound);
|
||
PushFromTop();
|
||
}
|
||
|
||
void Update(int var_index) {
|
||
if (vars_[var_index]->Min() == 1) {
|
||
sum_of_bound_variables_.SetValue(
|
||
solver(), sum_of_bound_variables_.Value() + coefs_[var_index]);
|
||
PushFromTop();
|
||
}
|
||
}
|
||
|
||
virtual string DebugString() const {
|
||
return StringPrintf("BooleanScalProd([%s], [%s]) <= %" GG_LL_FORMAT "d)",
|
||
DebugStringArray(vars_.get(), size_, ", ").c_str(),
|
||
Int64ArrayToString(coefs_.get(), size_, ", ").c_str(),
|
||
upper_bound_);
|
||
}
|
||
|
||
void Accept(ModelVisitor* const visitor) const {
|
||
visitor->BeginVisitConstraint(ModelVisitor::kScalProdLessOrEqual, this);
|
||
visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
|
||
vars_.get(),
|
||
size_);
|
||
visitor->VisitIntegerArrayArgument(ModelVisitor::kCoefficientsArgument,
|
||
coefs_.get(),
|
||
size_);
|
||
visitor->VisitIntegerArgument(ModelVisitor::kValueArgument,
|
||
upper_bound_);
|
||
visitor->EndVisitConstraint(ModelVisitor::kScalProdLessOrEqual, this);
|
||
}
|
||
|
||
private:
|
||
scoped_array<IntVar*> vars_;
|
||
int size_;
|
||
scoped_array<int64> coefs_;
|
||
int64 upper_bound_;
|
||
Rev<int> first_unbound_backward_;
|
||
Rev<int64> sum_of_bound_variables_;
|
||
Rev<int64> max_coefficient_;
|
||
};
|
||
|
||
// ----- PositiveBooleanScalProdEqVar -----
|
||
|
||
class PositiveBooleanScalProdEqVar : public CastConstraint {
|
||
public:
|
||
PositiveBooleanScalProdEqVar(Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size,
|
||
const int64* const coefs,
|
||
IntVar* const var)
|
||
: CastConstraint(s, var),
|
||
size_(size),
|
||
vars_(new IntVar*[size_]),
|
||
coefs_(new int64[size_]),
|
||
first_unbound_backward_(size_ - 1),
|
||
sum_of_bound_variables_(0LL),
|
||
sum_of_all_variables_(0LL),
|
||
max_coefficient_(0) {
|
||
CHECK_GT(size, 0);
|
||
CHECK(vars != NULL);
|
||
CHECK(coefs != NULL);
|
||
memcpy(vars_.get(), vars, size_ * sizeof(*vars));
|
||
memcpy(coefs_.get(), coefs, size_ * sizeof(*coefs));
|
||
SortBothChangeConstant(vars_.get(), coefs_.get(), &size_, true);
|
||
max_coefficient_.SetValue(s, coefs_[size_ - 1]);
|
||
}
|
||
|
||
PositiveBooleanScalProdEqVar(Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size,
|
||
const int* const coefs,
|
||
IntVar* const var)
|
||
: CastConstraint(s, var),
|
||
size_(size),
|
||
vars_(new IntVar*[size_]),
|
||
coefs_(new int64[size_]),
|
||
first_unbound_backward_(size_ - 1),
|
||
sum_of_bound_variables_(0LL),
|
||
sum_of_all_variables_(0LL),
|
||
max_coefficient_(0) {
|
||
CHECK_GT(size, 0);
|
||
CHECK(vars != NULL);
|
||
CHECK(coefs != NULL);
|
||
memcpy(vars_.get(), vars, size_ * sizeof(*vars));
|
||
for (int i = 0; i < size_; ++i) {
|
||
coefs_[i] = coefs[i];
|
||
}
|
||
SortBothChangeConstant(vars_.get(), coefs_.get(), &size_, true);
|
||
max_coefficient_.SetValue(s, coefs_[size_ - 1]);
|
||
}
|
||
|
||
virtual ~PositiveBooleanScalProdEqVar() {}
|
||
|
||
virtual void Post() {
|
||
for (int var_index = 0; var_index < size_; ++var_index) {
|
||
if (vars_[var_index]->Bound()) {
|
||
continue;
|
||
}
|
||
Demon* const d =
|
||
MakeConstraintDemon1(solver(),
|
||
this,
|
||
&PositiveBooleanScalProdEqVar::Update,
|
||
"Update",
|
||
var_index);
|
||
vars_[var_index]->WhenRange(d);
|
||
}
|
||
if (!target_var_->Bound()) {
|
||
Demon* const uv =
|
||
MakeConstraintDemon0(solver(),
|
||
this,
|
||
&PositiveBooleanScalProdEqVar::Propagate,
|
||
"Propagate");
|
||
target_var_->WhenRange(uv);
|
||
}
|
||
}
|
||
|
||
void Propagate() {
|
||
target_var_->SetRange(sum_of_bound_variables_.Value(),
|
||
sum_of_all_variables_.Value());
|
||
const int64 slack_up = target_var_->Max() - sum_of_bound_variables_.Value();
|
||
const int64 slack_down = sum_of_all_variables_.Value() - target_var_->Min();
|
||
const int64 max_coeff = max_coefficient_.Value();
|
||
if (slack_down < max_coeff || slack_up < max_coeff) {
|
||
int64 last_unbound = first_unbound_backward_.Value();
|
||
for (; last_unbound >= 0; --last_unbound) {
|
||
if (!vars_[last_unbound]->Bound()) {
|
||
if (coefs_[last_unbound] > slack_up) {
|
||
vars_[last_unbound]->SetValue(0);
|
||
} else if (coefs_[last_unbound] > slack_down) {
|
||
vars_[last_unbound]->SetValue(1);
|
||
} else {
|
||
max_coefficient_.SetValue(solver(), coefs_[last_unbound]);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
first_unbound_backward_.SetValue(solver(), last_unbound);
|
||
}
|
||
}
|
||
|
||
virtual void InitialPropagate() {
|
||
Solver* const s = solver();
|
||
int last_unbound = -1;
|
||
int64 sum_bound = 0;
|
||
int64 sum_all = 0;
|
||
for (int index = 0; index < size_; ++index) {
|
||
const int64 value = vars_[index]->Max() * coefs_[index];
|
||
sum_all += value;
|
||
if (vars_[index]->Bound()) {
|
||
sum_bound += value;
|
||
} else {
|
||
last_unbound = index;
|
||
}
|
||
}
|
||
sum_of_bound_variables_.SetValue(s, sum_bound);
|
||
sum_of_all_variables_.SetValue(s, sum_all);
|
||
first_unbound_backward_.SetValue(s, last_unbound);
|
||
Propagate();
|
||
}
|
||
|
||
void Update(int var_index) {
|
||
if (vars_[var_index]->Min() == 1) {
|
||
sum_of_bound_variables_.SetValue(
|
||
solver(), sum_of_bound_variables_.Value() + coefs_[var_index]);
|
||
} else {
|
||
sum_of_all_variables_.SetValue(
|
||
solver(), sum_of_all_variables_.Value() - coefs_[var_index]);
|
||
}
|
||
Propagate();
|
||
}
|
||
|
||
virtual string DebugString() const {
|
||
return StringPrintf(
|
||
"PositiveBooleanScal([%s], [%s]) == %s",
|
||
DebugStringArray(vars_.get(), size_, ", ").c_str(),
|
||
Int64ArrayToString(coefs_.get(), size_, ", ").c_str(),
|
||
target_var_->DebugString().c_str());
|
||
}
|
||
|
||
void Accept(ModelVisitor* const visitor) const {
|
||
visitor->BeginVisitConstraint(ModelVisitor::kScalProdEqual, this);
|
||
visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
|
||
vars_.get(),
|
||
size_);
|
||
visitor->VisitIntegerArrayArgument(ModelVisitor::kCoefficientsArgument,
|
||
coefs_.get(),
|
||
size_);
|
||
visitor->VisitIntegerExpressionArgument(ModelVisitor::kTargetArgument,
|
||
target_var_);
|
||
visitor->EndVisitConstraint(ModelVisitor::kScalProdEqual, this);
|
||
}
|
||
|
||
private:
|
||
int size_;
|
||
scoped_array<IntVar*> vars_;
|
||
scoped_array<int64> coefs_;
|
||
Rev<int> first_unbound_backward_;
|
||
Rev<int64> sum_of_bound_variables_;
|
||
Rev<int64> sum_of_all_variables_;
|
||
Rev<int64> max_coefficient_;
|
||
};
|
||
|
||
// ----- PositiveBooleanScalProd -----
|
||
|
||
class PositiveBooleanScalProd : public BaseIntExpr {
|
||
public:
|
||
// this constructor will copy the array. The caller can safely delete the
|
||
// exprs array himself
|
||
PositiveBooleanScalProd(Solver* const s,
|
||
const IntVar* const* vars,
|
||
int size,
|
||
const int64* const coefs)
|
||
: BaseIntExpr(s),
|
||
size_(size),
|
||
vars_(new IntVar*[size_]),
|
||
coefs_(new int64[size_]) {
|
||
CHECK_GT(size_, 0);
|
||
CHECK(vars != NULL);
|
||
CHECK(coefs != NULL);
|
||
memcpy(vars_.get(), vars, size_ * sizeof(*vars));
|
||
memcpy(coefs_.get(), coefs, size_ * sizeof(*coefs));
|
||
SortBothChangeConstant(vars_.get(), coefs_.get(), &size_, true);
|
||
for (int i = 0; i < size_; ++i) {
|
||
DCHECK_GE(coefs_[i], 0);
|
||
}
|
||
}
|
||
|
||
PositiveBooleanScalProd(Solver* const s,
|
||
const IntVar* const* vars,
|
||
int size,
|
||
const int* const coefs)
|
||
: BaseIntExpr(s),
|
||
size_(size),
|
||
vars_(new IntVar*[size_]),
|
||
coefs_(new int64[size_]) {
|
||
CHECK_GT(size_, 0);
|
||
CHECK(vars != NULL);
|
||
CHECK(coefs != NULL);
|
||
memcpy(vars_.get(), vars, size_ * sizeof(*vars));
|
||
for (int i = 0; i < size_; ++i) {
|
||
coefs_[i] = coefs[i];
|
||
DCHECK_GE(coefs_[i], 0);
|
||
}
|
||
SortBothChangeConstant(vars_.get(), coefs_.get(), &size_, true);
|
||
}
|
||
|
||
virtual ~PositiveBooleanScalProd() {}
|
||
|
||
virtual int64 Min() const {
|
||
int64 min = 0;
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Min()) {
|
||
min += coefs_[i];
|
||
}
|
||
}
|
||
return min;
|
||
}
|
||
|
||
virtual void SetMin(int64 m) {
|
||
SetRange(m, kint64max);
|
||
}
|
||
|
||
virtual int64 Max() const {
|
||
int64 max = 0;
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Max()) {
|
||
max += coefs_[i];
|
||
}
|
||
}
|
||
return max;
|
||
}
|
||
|
||
virtual void SetMax(int64 m) {
|
||
SetRange(kint64min, m);
|
||
}
|
||
|
||
virtual void SetRange(int64 l, int64 u) {
|
||
int64 current_min = 0;
|
||
int64 current_max = 0;
|
||
int64 diameter = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 coefficient = coefs_[i];
|
||
const int64 var_min = vars_[i]->Min() * coefficient;
|
||
const int64 var_max = vars_[i]->Max() * coefficient;
|
||
current_min += var_min;
|
||
current_max += var_max;
|
||
if (var_min != var_max) { // Coefficients are increasing.
|
||
diameter = var_max - var_min;
|
||
}
|
||
}
|
||
if (u >= current_max && l <= current_min) {
|
||
return;
|
||
}
|
||
if (u < current_min || l > current_max) {
|
||
solver()->Fail();
|
||
}
|
||
|
||
u = std::min(current_max, u);
|
||
l = std::max(l, current_min);
|
||
|
||
if (u - l > diameter) {
|
||
return;
|
||
}
|
||
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 coefficient = coefs_[i];
|
||
IntVar* const var = vars_[i];
|
||
const int64 new_min = l - current_max + var->Max() * coefficient;
|
||
const int64 new_max = u - current_min + var->Min() * coefficient;
|
||
if (new_max < 0 || new_min > coefficient || new_min > new_max) {
|
||
solver()->Fail();
|
||
}
|
||
if (new_min > 0LL) {
|
||
var->SetMin(1LL);
|
||
} else if (new_max < coefficient) {
|
||
var->SetMax(0LL);
|
||
}
|
||
}
|
||
}
|
||
|
||
virtual string DebugString() const {
|
||
return StringPrintf(
|
||
"PositiveBooleanScalProd([%s], [%s])",
|
||
DebugStringArray(vars_.get(), size_, ", ").c_str(),
|
||
Int64ArrayToString(coefs_.get(), size_, ", ").c_str());
|
||
}
|
||
|
||
virtual void WhenRange(Demon* d) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->WhenRange(d);
|
||
}
|
||
}
|
||
virtual IntVar* CastToVar() {
|
||
Solver* const s = solver();
|
||
int64 vmin = 0LL;
|
||
int64 vmax = 0LL;
|
||
Range(&vmin, &vmax);
|
||
IntVar* const var = solver()->MakeIntVar(vmin, vmax);
|
||
if (size_ > 0) {
|
||
CastConstraint* const ct = s->RevAlloc(
|
||
new PositiveBooleanScalProdEqVar(s,
|
||
vars_.get(),
|
||
size_,
|
||
coefs_.get(),
|
||
var));
|
||
s->AddCastConstraint(ct, var, this);
|
||
}
|
||
return var;
|
||
}
|
||
|
||
void Accept(ModelVisitor* const visitor) const {
|
||
visitor->BeginVisitIntegerExpression(ModelVisitor::kScalProd, this);
|
||
visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
|
||
vars_.get(),
|
||
size_);
|
||
visitor->VisitIntegerArrayArgument(ModelVisitor::kCoefficientsArgument,
|
||
coefs_.get(),
|
||
size_);
|
||
visitor->EndVisitIntegerExpression(ModelVisitor::kScalProd, this);
|
||
}
|
||
|
||
private:
|
||
int size_;
|
||
scoped_array<IntVar*> vars_;
|
||
scoped_array<int64> coefs_;
|
||
};
|
||
|
||
// ----- PositiveBooleanScalProdEqCst ----- (all constants >= 0)
|
||
|
||
class PositiveBooleanScalProdEqCst : public Constraint {
|
||
public:
|
||
PositiveBooleanScalProdEqCst(Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size,
|
||
const int64* const coefs,
|
||
int64 constant)
|
||
: Constraint(s),
|
||
size_(size),
|
||
vars_(new IntVar*[size_]),
|
||
coefs_(new int64[size_]),
|
||
first_unbound_backward_(size_ - 1),
|
||
sum_of_bound_variables_(0LL),
|
||
sum_of_all_variables_(0LL),
|
||
constant_(constant),
|
||
max_coefficient_(0) {
|
||
CHECK_GT(size, 0);
|
||
CHECK(vars != NULL);
|
||
CHECK(coefs != NULL);
|
||
memcpy(vars_.get(), vars, size_ * sizeof(*vars));
|
||
memcpy(coefs_.get(), coefs, size_ * sizeof(*coefs));
|
||
constant_ -= SortBothChangeConstant(vars_.get(),
|
||
coefs_.get(),
|
||
&size_,
|
||
false);
|
||
max_coefficient_.SetValue(s, coefs_[size_ - 1]);
|
||
}
|
||
|
||
PositiveBooleanScalProdEqCst(Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size,
|
||
const int* const coefs,
|
||
int64 constant)
|
||
: Constraint(s),
|
||
size_(size),
|
||
vars_(new IntVar*[size_]),
|
||
coefs_(new int64[size_]),
|
||
first_unbound_backward_(size_ - 1),
|
||
sum_of_bound_variables_(0LL),
|
||
sum_of_all_variables_(0LL),
|
||
constant_(constant),
|
||
max_coefficient_(0) {
|
||
CHECK_GT(size, 0);
|
||
CHECK(vars != NULL);
|
||
CHECK(coefs != NULL);
|
||
memcpy(vars_.get(), vars, size_ * sizeof(*vars));
|
||
for (int i = 0; i < size; ++i) {
|
||
coefs_[i] = coefs[i];
|
||
}
|
||
constant_ -= SortBothChangeConstant(vars_.get(),
|
||
coefs_.get(),
|
||
&size_,
|
||
false);
|
||
max_coefficient_.SetValue(s, coefs_[size_ - 1]);
|
||
}
|
||
|
||
virtual ~PositiveBooleanScalProdEqCst() {}
|
||
|
||
virtual void Post() {
|
||
for (int var_index = 0; var_index < size_; ++var_index) {
|
||
if (!vars_[var_index]->Bound()) {
|
||
Demon* const d =
|
||
MakeConstraintDemon1(solver(),
|
||
this,
|
||
&PositiveBooleanScalProdEqCst::Update,
|
||
"Update",
|
||
var_index);
|
||
vars_[var_index]->WhenRange(d);
|
||
}
|
||
}
|
||
}
|
||
|
||
void Propagate() {
|
||
if (sum_of_bound_variables_.Value() > constant_ ||
|
||
sum_of_all_variables_.Value() < constant_) {
|
||
solver()->Fail();
|
||
}
|
||
const int64 slack_up = constant_ - sum_of_bound_variables_.Value();
|
||
const int64 slack_down = sum_of_all_variables_.Value() - constant_;
|
||
const int64 max_coeff = max_coefficient_.Value();
|
||
if (slack_down < max_coeff || slack_up < max_coeff) {
|
||
int64 last_unbound = first_unbound_backward_.Value();
|
||
for (; last_unbound >= 0; --last_unbound) {
|
||
if (!vars_[last_unbound]->Bound()) {
|
||
if (coefs_[last_unbound] > slack_up) {
|
||
vars_[last_unbound]->SetValue(0);
|
||
} else if (coefs_[last_unbound] > slack_down) {
|
||
vars_[last_unbound]->SetValue(1);
|
||
} else {
|
||
max_coefficient_.SetValue(solver(), coefs_[last_unbound]);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
first_unbound_backward_.SetValue(solver(), last_unbound);
|
||
}
|
||
}
|
||
|
||
virtual void InitialPropagate() {
|
||
Solver* const s = solver();
|
||
int last_unbound = -1;
|
||
int64 sum_bound = 0LL;
|
||
int64 sum_all = 0LL;
|
||
for (int index = 0; index < size_; ++index) {
|
||
const int64 value = vars_[index]->Max() * coefs_[index];
|
||
sum_all += value;
|
||
if (vars_[index]->Bound()) {
|
||
sum_bound += value;
|
||
} else {
|
||
last_unbound = index;
|
||
}
|
||
}
|
||
sum_of_bound_variables_.SetValue(s, sum_bound);
|
||
sum_of_all_variables_.SetValue(s, sum_all);
|
||
first_unbound_backward_.SetValue(s, last_unbound);
|
||
Propagate();
|
||
}
|
||
|
||
void Update(int var_index) {
|
||
if (vars_[var_index]->Min() == 1) {
|
||
sum_of_bound_variables_.SetValue(
|
||
solver(), sum_of_bound_variables_.Value() + coefs_[var_index]);
|
||
} else {
|
||
sum_of_all_variables_.SetValue(
|
||
solver(), sum_of_all_variables_.Value() - coefs_[var_index]);
|
||
}
|
||
Propagate();
|
||
}
|
||
|
||
virtual string DebugString() const {
|
||
return StringPrintf(
|
||
"PositiveBooleanScalProd([%s], [%s]) == %" GG_LL_FORMAT "d",
|
||
DebugStringArray(vars_.get(), size_, ", ").c_str(),
|
||
Int64ArrayToString(coefs_.get(), size_, ", ").c_str(),
|
||
constant_);
|
||
}
|
||
|
||
void Accept(ModelVisitor* const visitor) const {
|
||
visitor->BeginVisitConstraint(ModelVisitor::kScalProdEqual, this);
|
||
visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
|
||
vars_.get(),
|
||
size_);
|
||
visitor->VisitIntegerArrayArgument(ModelVisitor::kCoefficientsArgument,
|
||
coefs_.get(),
|
||
size_);
|
||
visitor->VisitIntegerArgument(ModelVisitor::kValueArgument,
|
||
constant_);
|
||
visitor->EndVisitConstraint(ModelVisitor::kScalProdEqual, this);
|
||
}
|
||
|
||
private:
|
||
int size_;
|
||
scoped_array<IntVar*> vars_;
|
||
scoped_array<int64> coefs_;
|
||
Rev<int> first_unbound_backward_;
|
||
Rev<int64> sum_of_bound_variables_;
|
||
Rev<int64> sum_of_all_variables_;
|
||
int64 constant_;
|
||
Rev<int64> max_coefficient_;
|
||
};
|
||
|
||
} // namespace
|
||
|
||
// ----- API -----
|
||
|
||
IntExpr* Solver::MakeSum(const std::vector<IntVar*>& vars) {
|
||
const int size = vars.size();
|
||
if (size == 0) {
|
||
return MakeIntConst(0LL);
|
||
} else if (size == 1) {
|
||
return vars[0];
|
||
} else if (size == 2) {
|
||
return MakeSum(vars[0], vars[1]);
|
||
} else {
|
||
IntExpr* const cache =
|
||
model_cache_->FindVarArrayExpression(vars, ModelCache::VAR_ARRAY_SUM);
|
||
if (cache != NULL) {
|
||
return cache->Var();
|
||
} else {
|
||
int64 new_min = 0;
|
||
int64 new_max = 0;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (new_min != kint64min) {
|
||
new_min = CapAdd(vars[i]->Min(), new_min);
|
||
}
|
||
if (new_max != kint64max) {
|
||
new_max = CapAdd(vars[i]->Max(), new_max);
|
||
}
|
||
}
|
||
const bool all_booleans = AreAllBooleans(vars.data(), vars.size());
|
||
|
||
const string name = all_booleans ?
|
||
StringPrintf("BooleanSum([%s])", NameVector(vars, ", ").c_str()) :
|
||
StringPrintf("Sum([%s])", NameVector(vars, ", ").c_str());
|
||
IntVar* const sum_var = MakeIntVar(new_min, new_max, name);
|
||
if (all_booleans) {
|
||
AddConstraint(RevAlloc(
|
||
new SumBooleanEqualToVar(this, vars.data(), vars.size(), sum_var)));
|
||
} else if (new_min != kint64min && new_max != kint64max) {
|
||
AddConstraint(RevAlloc(new SumConstraint(this, vars, sum_var)));
|
||
} else {
|
||
AddConstraint(RevAlloc(new SafeSumConstraint(this, vars, sum_var)));
|
||
}
|
||
model_cache_->InsertVarArrayExpression(
|
||
sum_var, vars, ModelCache::VAR_ARRAY_SUM);
|
||
return sum_var;
|
||
}
|
||
}
|
||
}
|
||
|
||
IntExpr* Solver::MakeMin(const std::vector<IntVar*>& vars) {
|
||
const int size = vars.size();
|
||
if (size == 0) {
|
||
return MakeIntConst(0LL);
|
||
} else if (size == 1) {
|
||
return vars[0];
|
||
} else if (size == 2) {
|
||
return MakeMin(vars[0], vars[1]);
|
||
} else {
|
||
IntExpr* const cache =
|
||
model_cache_->FindVarArrayExpression(vars, ModelCache::VAR_ARRAY_MIN);
|
||
if (cache != NULL) {
|
||
return cache->Var();
|
||
} else {
|
||
if (AreAllBooleans(vars.data(), vars.size())) {
|
||
IntVar* const new_var = MakeBoolVar();
|
||
AddConstraint(RevAlloc(new ArrayBoolAndEq(this, vars, new_var)));
|
||
model_cache_->InsertVarArrayExpression(
|
||
new_var, vars, ModelCache::VAR_ARRAY_MIN);
|
||
return new_var;
|
||
} else {
|
||
int64 new_min = kint64max;
|
||
int64 new_max = kint64max;
|
||
for (int i = 0; i < size; ++i) {
|
||
new_min = std::min(new_min, vars[i]->Min());
|
||
new_max = std::min(new_max, vars[i]->Max());
|
||
}
|
||
IntVar* const new_var = MakeIntVar(new_min, new_max);
|
||
AddConstraint(RevAlloc(new MinConstraint(this, vars, new_var)));
|
||
model_cache_->InsertVarArrayExpression(
|
||
new_var, vars, ModelCache::VAR_ARRAY_MIN);
|
||
return new_var;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
IntExpr* Solver::MakeMax(const std::vector<IntVar*>& vars) {
|
||
const int size = vars.size();
|
||
if (size == 0) {
|
||
return MakeIntConst(0LL);
|
||
} else if (size == 1) {
|
||
return vars[0];
|
||
} else if (size == 2) {
|
||
return MakeMax(vars[0], vars[1]);
|
||
} else {
|
||
IntExpr* const cache =
|
||
model_cache_->FindVarArrayExpression(vars, ModelCache::VAR_ARRAY_MAX);
|
||
if (cache != NULL) {
|
||
return cache->Var();
|
||
} else {
|
||
if (AreAllBooleans(vars.data(), vars.size())) {
|
||
IntVar* const new_var = MakeBoolVar();
|
||
AddConstraint(RevAlloc(new ArrayBoolOrEq(this, vars, new_var)));
|
||
model_cache_->InsertVarArrayExpression(
|
||
new_var, vars, ModelCache::VAR_ARRAY_MIN);
|
||
return new_var;
|
||
} else {
|
||
int64 new_min = kint64min;
|
||
int64 new_max = kint64min;
|
||
for (int i = 0; i < size; ++i) {
|
||
new_min = std::max(new_min, vars[i]->Min());
|
||
new_max = std::max(new_max, vars[i]->Max());
|
||
}
|
||
IntVar* const new_var = MakeIntVar(new_min, new_max);
|
||
AddConstraint(RevAlloc(new MaxConstraint(this, vars, new_var)));
|
||
model_cache_->InsertVarArrayExpression(
|
||
new_var, vars, ModelCache::VAR_ARRAY_MAX);
|
||
return new_var;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
Constraint* Solver::MakeMinEquality(const std::vector<IntVar*>& vars,
|
||
IntVar* const min_var) {
|
||
const int size = vars.size();
|
||
if (size > 2) {
|
||
if (AreAllBooleans(vars.data(), vars.size())) {
|
||
return RevAlloc(new ArrayBoolAndEq(this, vars, min_var));
|
||
} else {
|
||
return RevAlloc(new MinConstraint(this, vars, min_var));
|
||
}
|
||
} else if (size == 2) {
|
||
return MakeEquality(MakeMin(vars[0], vars[1])->Var(), min_var);
|
||
} else if (size == 1) {
|
||
return MakeEquality(vars[0], min_var);
|
||
} else {
|
||
return MakeEquality(min_var, Zero());
|
||
}
|
||
}
|
||
|
||
Constraint* Solver::MakeMaxEquality(const std::vector<IntVar*>& vars,
|
||
IntVar* const max_var) {
|
||
const int size = vars.size();
|
||
if (size > 2) {
|
||
if (AreAllBooleans(vars.data(), vars.size())) {
|
||
return RevAlloc(new ArrayBoolOrEq(this, vars, max_var));
|
||
} else {
|
||
return RevAlloc(new MaxConstraint(this, vars, max_var));
|
||
}
|
||
} else if (size == 2) {
|
||
return MakeEquality(MakeMax(vars[0], vars[1])->Var(), max_var);
|
||
} else if (size == 1) {
|
||
return MakeEquality(vars[0], max_var);
|
||
} else {
|
||
return MakeEquality(max_var, Zero());
|
||
}
|
||
}
|
||
|
||
Constraint* Solver::MakeSumLessOrEqual(const std::vector<IntVar*>& vars, int64 cst) {
|
||
const int size = vars.size();
|
||
if (cst == 1LL && AreAllBooleans(vars.data(), size) && size > 2) {
|
||
return RevAlloc(new SumBooleanLessOrEqualToOne(this, vars.data(), size));
|
||
} else {
|
||
return MakeLessOrEqual(MakeSum(vars), cst);
|
||
}
|
||
}
|
||
|
||
Constraint* Solver::MakeSumGreaterOrEqual(const std::vector<IntVar*>& vars,
|
||
int64 cst) {
|
||
const int size = vars.size();
|
||
if (cst == 1LL && AreAllBooleans(vars.data(), size) && size > 2) {
|
||
return RevAlloc(new SumBooleanGreaterOrEqualToOne(this, vars.data(), size));
|
||
} else {
|
||
return MakeGreaterOrEqual(MakeSum(vars), cst);
|
||
}
|
||
}
|
||
|
||
Constraint* Solver::MakeSumEquality(const std::vector<IntVar*>& vars, int64 cst) {
|
||
const int size = vars.size();
|
||
if (AreAllBooleans(vars.data(), size) && size > 2) {
|
||
if (cst == 1) {
|
||
return RevAlloc(new SumBooleanEqualToOne(this, vars.data(), size));
|
||
} else if (cst < 0 || cst > size) {
|
||
return MakeFalseConstraint();
|
||
} else {
|
||
return RevAlloc(new SumBooleanEqualToVar(this,
|
||
vars.data(),
|
||
size,
|
||
MakeIntConst(cst)));
|
||
}
|
||
} else {
|
||
if (vars.size() == 1) {
|
||
return MakeEquality(vars[0], cst);
|
||
} else if (vars.size() == 2) {
|
||
return MakeEquality(vars[0], MakeDifference(cst, vars[1])->Var());
|
||
}
|
||
if (DetectSumOverflow(vars)) {
|
||
return RevAlloc(new SafeSumConstraint(this, vars, MakeIntConst(cst)));
|
||
} else {
|
||
return RevAlloc(new SumConstraint(this, vars, MakeIntConst(cst)));
|
||
}
|
||
}
|
||
}
|
||
|
||
Constraint* Solver::MakeSumEquality(const std::vector<IntVar*>& vars,
|
||
IntVar* const var) {
|
||
const int size = vars.size();
|
||
if (AreAllBooleans(vars.data(), size) && size > 2) {
|
||
return RevAlloc(new SumBooleanEqualToVar(this, vars.data(), size, var));
|
||
} else if (size == 0) {
|
||
return MakeEquality(var, Zero());
|
||
} else if (size == 1) {
|
||
return MakeEquality(vars[0], var);
|
||
} else if (size == 2) {
|
||
return MakeEquality(MakeSum(vars[0], vars[1])->Var(), var);
|
||
} else {
|
||
if (DetectSumOverflow(vars)) {
|
||
return RevAlloc(new SafeSumConstraint(this, vars, var));
|
||
} else {
|
||
return RevAlloc(new SumConstraint(this, vars, var));
|
||
}
|
||
}
|
||
}
|
||
|
||
namespace {
|
||
template<class T> Constraint* MakeScalProdEqualityFct(Solver* const solver,
|
||
IntVar* const * vars,
|
||
int size,
|
||
T const * coefficients,
|
||
int64 cst) {
|
||
if (size == 0 || AreAllNull<T>(coefficients, size)) {
|
||
return cst == 0 ? solver->MakeTrueConstraint()
|
||
: solver->MakeFalseConstraint();
|
||
}
|
||
if (AreAllBooleans(vars, size) &&
|
||
AreAllPositive<T>(coefficients, size) &&
|
||
size > 2) {
|
||
// TODO(user) : bench BooleanScalProdEqVar with IntConst.
|
||
return solver->RevAlloc(new PositiveBooleanScalProdEqCst(solver,
|
||
vars,
|
||
size,
|
||
coefficients,
|
||
cst));
|
||
}
|
||
// Some simplications
|
||
int constants = 0;
|
||
int positives = 0;
|
||
int negatives = 0;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
constants++;
|
||
} else if (coefficients[i] > 0) {
|
||
positives++;
|
||
} else {
|
||
negatives++;
|
||
}
|
||
}
|
||
if (positives > 0 && negatives > 0) {
|
||
std::vector<IntVar*> pos_terms;
|
||
std::vector<IntVar*> neg_terms;
|
||
int64 rhs = cst;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
rhs -= coefficients[i] * vars[i]->Min();
|
||
} else if (coefficients[i] > 0) {
|
||
pos_terms.push_back(solver->MakeProd(vars[i], coefficients[i])->Var());
|
||
} else {
|
||
neg_terms.push_back(solver->MakeProd(vars[i], -coefficients[i])->Var());
|
||
}
|
||
}
|
||
if (negatives == 1) {
|
||
if (rhs != 0) {
|
||
pos_terms.push_back(solver->MakeIntConst(-rhs));
|
||
}
|
||
return solver->MakeSumEquality(pos_terms, neg_terms[0]);
|
||
} else if (positives == 1) {
|
||
if (rhs != 0) {
|
||
neg_terms.push_back(solver->MakeIntConst(rhs));
|
||
}
|
||
return solver->MakeSumEquality(neg_terms, pos_terms[0]);
|
||
} else {
|
||
if (rhs != 0) {
|
||
neg_terms.push_back(solver->MakeIntConst(rhs));
|
||
}
|
||
return solver->MakeEquality(
|
||
solver->MakeSum(pos_terms)->Var(),
|
||
solver->MakeSum(neg_terms)->Var());
|
||
}
|
||
} else if (positives == 1) {
|
||
IntVar* pos_term = NULL;
|
||
int64 rhs = cst;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
rhs -= coefficients[i] * vars[i]->Min();
|
||
} else if (coefficients[i] > 0) {
|
||
pos_term = solver->MakeProd(vars[i], coefficients[i])->Var();
|
||
} else {
|
||
LOG(FATAL) << "Should not be here";
|
||
}
|
||
}
|
||
return solver->MakeEquality(pos_term, rhs);
|
||
} else if (negatives == 1) {
|
||
IntVar* neg_term = NULL;
|
||
int64 rhs = cst;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
rhs -= coefficients[i] * vars[i]->Min();
|
||
} else if (coefficients[i] > 0) {
|
||
LOG(FATAL) << "Should not be here";
|
||
} else {
|
||
neg_term = solver->MakeProd(vars[i], -coefficients[i])->Var();
|
||
}
|
||
}
|
||
return solver->MakeEquality(neg_term, -rhs);
|
||
} else if (positives > 1) {
|
||
std::vector<IntVar*> pos_terms;
|
||
int64 rhs = cst;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
rhs -= coefficients[i] * vars[i]->Min();
|
||
} else if (coefficients[i] > 0) {
|
||
pos_terms.push_back(solver->MakeProd(vars[i], coefficients[i])->Var());
|
||
} else {
|
||
LOG(FATAL) << "Should not be here";
|
||
}
|
||
}
|
||
return solver->MakeSumEquality(pos_terms, rhs);
|
||
} else if (negatives > 1) {
|
||
std::vector<IntVar*> neg_terms;
|
||
int64 rhs = cst;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
rhs -= coefficients[i] * vars[i]->Min();
|
||
} else if (coefficients[i] > 0) {
|
||
LOG(FATAL) << "Should not be here";
|
||
} else {
|
||
neg_terms.push_back(solver->MakeProd(vars[i], -coefficients[i])->Var());
|
||
}
|
||
}
|
||
return solver->MakeSumEquality(neg_terms, -rhs);
|
||
}
|
||
std::vector<IntVar*> terms;
|
||
for (int i = 0; i < size; ++i) {
|
||
terms.push_back(solver->MakeProd(vars[i], coefficients[i])->Var());
|
||
}
|
||
return solver->MakeSumEquality(terms, solver->MakeIntConst(cst));
|
||
}
|
||
|
||
template<class T> Constraint* MakeScalProdEqualityVarFct(Solver* const solver,
|
||
IntVar* const * vars,
|
||
int size,
|
||
T const * coefficients,
|
||
IntVar* const target) {
|
||
if (size == 0 || AreAllNull<T>(coefficients, size)) {
|
||
return solver->MakeEquality(target, Zero());
|
||
}
|
||
if (AreAllBooleans(vars, size) && AreAllPositive<T>(coefficients, size)) {
|
||
// TODO(user) : bench BooleanScalProdEqVar with IntConst.
|
||
return solver->RevAlloc(new PositiveBooleanScalProdEqVar(solver,
|
||
vars,
|
||
size,
|
||
coefficients,
|
||
target));
|
||
}
|
||
std::vector<IntVar*> terms;
|
||
for (int i = 0; i < size; ++i) {
|
||
terms.push_back(solver->MakeProd(vars[i], coefficients[i])->Var());
|
||
}
|
||
return solver->MakeSumEquality(terms, target);
|
||
}
|
||
} // namespace
|
||
|
||
Constraint* Solver::MakeScalProdEquality(const std::vector<IntVar*>& vars,
|
||
const std::vector<int64>& coefficients,
|
||
int64 cst) {
|
||
DCHECK_EQ(vars.size(), coefficients.size());
|
||
return MakeScalProdEqualityFct<int64>(this,
|
||
vars.data(),
|
||
vars.size(),
|
||
coefficients.data(),
|
||
cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdEquality(const std::vector<IntVar*>& vars,
|
||
const std::vector<int>& coefficients,
|
||
int64 cst) {
|
||
DCHECK_EQ(vars.size(), coefficients.size());
|
||
return MakeScalProdEqualityFct<int>(this,
|
||
vars.data(),
|
||
vars.size(),
|
||
coefficients.data(),
|
||
cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdEquality(const std::vector<IntVar*>& vars,
|
||
const std::vector<int64>& coefficients,
|
||
IntVar* const target) {
|
||
DCHECK_EQ(vars.size(), coefficients.size());
|
||
return MakeScalProdEqualityVarFct<int64>(this,
|
||
vars.data(),
|
||
vars.size(),
|
||
coefficients.data(),
|
||
target);
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdEquality(const std::vector<IntVar*>& vars,
|
||
const std::vector<int>& coefficients,
|
||
IntVar* const target) {
|
||
DCHECK_EQ(vars.size(), coefficients.size());
|
||
return MakeScalProdEqualityVarFct<int>(this,
|
||
vars.data(),
|
||
vars.size(),
|
||
coefficients.data(),
|
||
target);
|
||
}
|
||
|
||
namespace {
|
||
template<class T>
|
||
Constraint* MakeScalProdGreaterOrEqualFct(Solver* solver,
|
||
IntVar* const * vars,
|
||
int size,
|
||
T const * coefficients,
|
||
int64 cst) {
|
||
if (size == 0 || AreAllNull<T>(coefficients, size)) {
|
||
return cst <= 0 ? solver->MakeTrueConstraint()
|
||
: solver->MakeFalseConstraint();
|
||
}
|
||
if (cst == 1 &&
|
||
AreAllBooleans(vars, size) &&
|
||
AreAllPositive(coefficients, size)) { // can move all coefficients to 1.
|
||
std::vector<IntVar*> terms;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] > 0) {
|
||
terms.push_back(vars[i]);
|
||
}
|
||
}
|
||
return solver->MakeSumGreaterOrEqual(terms, 1);
|
||
}
|
||
std::vector<IntVar*> terms;
|
||
for (int i = 0; i < size; ++i) {
|
||
terms.push_back(solver->MakeProd(vars[i], coefficients[i])->Var());
|
||
}
|
||
return solver->MakeSumGreaterOrEqual(terms, cst);
|
||
}
|
||
|
||
#define IS_TYPE(type, tag) type.compare(ModelVisitor::tag) == 0
|
||
|
||
class ExprLinearizer : public ModelParser {
|
||
public:
|
||
ExprLinearizer(hash_map<const IntExpr*, int64>* const map)
|
||
: map_(map), constant_(0) {}
|
||
|
||
virtual ~ExprLinearizer() {}
|
||
|
||
// Begin/End visit element.
|
||
virtual void BeginVisitModel(const string& solver_name) {
|
||
LOG(FATAL) << "Should not be here";
|
||
}
|
||
|
||
virtual void EndVisitModel(const string& solver_name) {
|
||
LOG(FATAL) << "Should not be here";
|
||
}
|
||
|
||
virtual void BeginVisitConstraint(const string& type_name,
|
||
const Constraint* const constraint) {
|
||
LOG(FATAL) << "Should not be here";
|
||
}
|
||
|
||
virtual void EndVisitConstraint(const string& type_name,
|
||
const Constraint* const constraint) {
|
||
LOG(FATAL) << "Should not be here";
|
||
}
|
||
|
||
virtual void BeginVisitExtension(const string& type) {
|
||
LOG(FATAL) << "Should not be here";
|
||
}
|
||
|
||
virtual void EndVisitExtension(const string& type) {
|
||
LOG(FATAL) << "Should not be here";
|
||
}
|
||
virtual void BeginVisitIntegerExpression(const string& type_name,
|
||
const IntExpr* const expr) {
|
||
BeginVisit(true);
|
||
}
|
||
|
||
virtual void EndVisitIntegerExpression(const string& type_name,
|
||
const IntExpr* const expr) {
|
||
if (IS_TYPE(type_name, kSum)) {
|
||
VisitSum(expr);
|
||
} else if (IS_TYPE(type_name, kScalProd)) {
|
||
VisitScalProd(expr);
|
||
} else if (IS_TYPE(type_name, kDifference)) {
|
||
VisitDifference(expr);
|
||
} else if (IS_TYPE(type_name, kOpposite)) {
|
||
VisitOpposite(expr);
|
||
} else if (IS_TYPE(type_name, kProduct)) {
|
||
VisitProduct(expr);
|
||
} else {
|
||
VisitIntegerExpression(expr);
|
||
}
|
||
EndVisit();
|
||
}
|
||
|
||
virtual void VisitIntegerVariable(const IntVar* const variable,
|
||
const string& operation,
|
||
int64 value,
|
||
const IntVar* const delegate) {
|
||
if (operation == ModelVisitor::kSumOperation) {
|
||
AddConstant(value);
|
||
VisitSubExpression(delegate);
|
||
} else if (operation == ModelVisitor::kDifferenceOperation) {
|
||
AddConstant(value);
|
||
PushMultiplier(-1);
|
||
VisitSubExpression(delegate);
|
||
PopMultiplier();
|
||
} else if (operation == ModelVisitor::kProductOperation) {
|
||
PushMultiplier(value);
|
||
VisitSubExpression(delegate);
|
||
PopMultiplier();
|
||
}
|
||
}
|
||
|
||
virtual void VisitIntegerVariable(const IntVar* const variable,
|
||
const IntExpr* const delegate) {
|
||
if (delegate == NULL) {
|
||
if (variable->Bound()) {
|
||
AddConstant(variable->Min());
|
||
} else {
|
||
RegisterExpression(variable, 1);
|
||
}
|
||
} else {
|
||
VisitSubExpression(delegate);
|
||
}
|
||
}
|
||
|
||
// Visit integer arguments.
|
||
virtual void VisitIntegerArgument(const string& arg_name, int64 value) {
|
||
Top()->SetIntegerArgument(arg_name, value);
|
||
}
|
||
|
||
virtual void VisitIntegerArrayArgument(const string& arg_name,
|
||
const int64* const values,
|
||
int size) {
|
||
Top()->SetIntegerArrayArgument(arg_name, values, size);
|
||
}
|
||
|
||
virtual void VisitIntegerMatrixArgument(const string& arg_name,
|
||
const IntTupleSet& values) {
|
||
Top()->SetIntegerMatrixArgument(arg_name, values);
|
||
}
|
||
|
||
// Visit integer expression argument.
|
||
virtual void VisitIntegerExpressionArgument(
|
||
const string& arg_name,
|
||
const IntExpr* const argument) {
|
||
Top()->SetIntegerExpressionArgument(arg_name, argument);
|
||
}
|
||
|
||
virtual void VisitIntegerVariableArrayArgument(
|
||
const string& arg_name,
|
||
const IntVar* const * arguments,
|
||
int size) {
|
||
Top()->SetIntegerVariableArrayArgument(arg_name, arguments, size);
|
||
}
|
||
|
||
// Visit interval argument.
|
||
virtual void VisitIntervalArgument(const string& arg_name,
|
||
const IntervalVar* const argument) {}
|
||
|
||
virtual void VisitIntervalArrayArgument(const string& arg_name,
|
||
const IntervalVar* const * argument,
|
||
int size) {}
|
||
|
||
void Visit(const IntExpr* const expr, int64 multiplier) {
|
||
PushMultiplier(multiplier);
|
||
expr->Accept(this);
|
||
PopMultiplier();
|
||
}
|
||
|
||
int64 Constant() const { return constant_; }
|
||
|
||
private:
|
||
void BeginVisit(bool active) {
|
||
PushArgumentHolder();
|
||
}
|
||
|
||
void EndVisit() {
|
||
PopArgumentHolder();
|
||
}
|
||
|
||
void VisitSubExpression(const IntExpr* const cp_expr) {
|
||
cp_expr->Accept(this);
|
||
}
|
||
|
||
void VisitSum(const IntExpr* const cp_expr) {
|
||
if (Top()->HasIntegerVariableArrayArgument(ModelVisitor::kVarsArgument)) {
|
||
const std::vector<const IntVar*>& cp_vars =
|
||
Top()->FindIntegerVariableArrayArgumentOrDie(
|
||
ModelVisitor::kVarsArgument);
|
||
for (int i = 0; i < cp_vars.size(); ++i) {
|
||
VisitSubExpression(cp_vars[i]);
|
||
}
|
||
} else if (Top()->HasIntegerExpressionArgument(
|
||
ModelVisitor::kLeftArgument)) {
|
||
const IntExpr* const left =
|
||
Top()->FindIntegerExpressionArgumentOrDie(
|
||
ModelVisitor::kLeftArgument);
|
||
const IntExpr* const right =
|
||
Top()->FindIntegerExpressionArgumentOrDie(
|
||
ModelVisitor::kRightArgument);
|
||
VisitSubExpression(left);
|
||
VisitSubExpression(right);
|
||
} else {
|
||
const IntExpr* const expr =
|
||
Top()->FindIntegerExpressionArgumentOrDie(
|
||
ModelVisitor::kExpressionArgument);
|
||
const int64 value =
|
||
Top()->FindIntegerArgumentOrDie(ModelVisitor::kValueArgument);
|
||
VisitSubExpression(expr);
|
||
AddConstant(value);
|
||
}
|
||
}
|
||
|
||
void VisitScalProd(const IntExpr* const cp_expr) {
|
||
const std::vector<const IntVar*>& cp_vars =
|
||
Top()->FindIntegerVariableArrayArgumentOrDie(
|
||
ModelVisitor::kVarsArgument);
|
||
const std::vector<int64>& cp_coefficients =
|
||
Top()->FindIntegerArrayArgumentOrDie(
|
||
ModelVisitor::kCoefficientsArgument);
|
||
CHECK_EQ(cp_vars.size(), cp_coefficients.size());
|
||
for (int i = 0; i < cp_vars.size(); ++i) {
|
||
const int64 coefficient = cp_coefficients[i];
|
||
PushMultiplier(coefficient);
|
||
VisitSubExpression(cp_vars[i]);
|
||
PopMultiplier();
|
||
}
|
||
}
|
||
|
||
void VisitDifference(const IntExpr* const cp_expr) {
|
||
if (Top()->HasIntegerExpressionArgument(ModelVisitor::kLeftArgument)) {
|
||
const IntExpr* const left =
|
||
Top()->FindIntegerExpressionArgumentOrDie(
|
||
ModelVisitor::kLeftArgument);
|
||
const IntExpr* const right =
|
||
Top()->FindIntegerExpressionArgumentOrDie(
|
||
ModelVisitor::kRightArgument);
|
||
VisitSubExpression(left);
|
||
PushMultiplier(-1);
|
||
VisitSubExpression(right);
|
||
PopMultiplier();
|
||
} else {
|
||
const IntExpr* const expr =
|
||
Top()->FindIntegerExpressionArgumentOrDie(
|
||
ModelVisitor::kExpressionArgument);
|
||
const int64 value =
|
||
Top()->FindIntegerArgumentOrDie(ModelVisitor::kValueArgument);
|
||
AddConstant(value);
|
||
PushMultiplier(-1);
|
||
VisitSubExpression(expr);
|
||
PopMultiplier();
|
||
}
|
||
}
|
||
|
||
void VisitOpposite(const IntExpr* const cp_expr) {
|
||
const IntExpr* const expr =
|
||
Top()->FindIntegerExpressionArgumentOrDie(
|
||
ModelVisitor::kExpressionArgument);
|
||
PushMultiplier(-1);
|
||
VisitSubExpression(expr);
|
||
PopMultiplier();
|
||
}
|
||
|
||
void VisitProduct(const IntExpr* const cp_expr) {
|
||
if (Top()->HasIntegerExpressionArgument(
|
||
ModelVisitor::kExpressionArgument)) {
|
||
const IntExpr* const expr =
|
||
Top()->FindIntegerExpressionArgumentOrDie(
|
||
ModelVisitor::kExpressionArgument);
|
||
const int64 value =
|
||
Top()->FindIntegerArgumentOrDie(ModelVisitor::kValueArgument);
|
||
PushMultiplier(value);
|
||
VisitSubExpression(expr);
|
||
PopMultiplier();
|
||
} else {
|
||
RegisterExpression(cp_expr, 1);
|
||
}
|
||
}
|
||
|
||
void VisitIntegerExpression(const IntExpr* const cp_expr) {
|
||
RegisterExpression(cp_expr, 1);
|
||
}
|
||
|
||
void RegisterExpression(const IntExpr* const expr, int64 coef) {
|
||
(*map_)[expr] += coef * multipliers_.back();
|
||
}
|
||
|
||
void AddConstant(int64 constant) {
|
||
constant_ += constant * multipliers_.back();
|
||
}
|
||
|
||
void PushMultiplier(int64 multiplier) {
|
||
if (multipliers_.empty()) {
|
||
multipliers_.push_back(multiplier);
|
||
} else {
|
||
multipliers_.push_back(multiplier * multipliers_.back());
|
||
}
|
||
}
|
||
|
||
void PopMultiplier() {
|
||
multipliers_.pop_back();
|
||
}
|
||
|
||
hash_map<const IntExpr*, int64>* const map_;
|
||
std::vector<int64> multipliers_;
|
||
int64 constant_;
|
||
};
|
||
} // namespace
|
||
|
||
Constraint* Solver::MakeScalProdGreaterOrEqual(const std::vector<IntVar*>& vars,
|
||
const std::vector<int64>& coeffs,
|
||
int64 cst) {
|
||
DCHECK_EQ(vars.size(), coeffs.size());
|
||
return MakeScalProdGreaterOrEqualFct<int64>(this,
|
||
vars.data(),
|
||
vars.size(),
|
||
coeffs.data(),
|
||
cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdGreaterOrEqual(const std::vector<IntVar*>& vars,
|
||
const std::vector<int>& coeffs,
|
||
int64 cst) {
|
||
DCHECK_EQ(vars.size(), coeffs.size());
|
||
return MakeScalProdGreaterOrEqualFct<int>(this,
|
||
vars.data(),
|
||
vars.size(),
|
||
coeffs.data(),
|
||
cst);
|
||
}
|
||
|
||
namespace {
|
||
template<class T> Constraint* MakeScalProdLessOrEqualFct(Solver* solver,
|
||
IntVar* const * vars,
|
||
int size,
|
||
T const * coefficients,
|
||
int64 upper_bound) {
|
||
if (size == 0 || AreAllNull<T>(coefficients, size)) {
|
||
return upper_bound >= 0 ? solver->MakeTrueConstraint()
|
||
: solver->MakeFalseConstraint();
|
||
}
|
||
// TODO(user) : compute constant on the fly.
|
||
if (AreAllBoundOrNull(vars, coefficients, size)) {
|
||
int64 cst = 0;
|
||
for (int i = 0; i < size; ++i) {
|
||
cst += vars[i]->Min() * coefficients[i];
|
||
}
|
||
return cst <= upper_bound ?
|
||
solver->MakeTrueConstraint() :
|
||
solver->MakeFalseConstraint();
|
||
}
|
||
if (AreAllBooleans(vars, size) && AreAllPositive<T>(coefficients, size)) {
|
||
return solver->RevAlloc(new BooleanScalProdLessConstant(solver,
|
||
vars,
|
||
size,
|
||
coefficients,
|
||
upper_bound));
|
||
}
|
||
// Some simplications
|
||
int constants = 0;
|
||
int positives = 0;
|
||
int negatives = 0;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
constants++;
|
||
} else if (coefficients[i] > 0) {
|
||
positives++;
|
||
} else {
|
||
negatives++;
|
||
}
|
||
}
|
||
if (positives > 0 && negatives > 0) {
|
||
std::vector<IntVar*> pos_terms;
|
||
std::vector<IntVar*> neg_terms;
|
||
int64 rhs = upper_bound;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
rhs -= coefficients[i] * vars[i]->Min();
|
||
} else if (coefficients[i] > 0) {
|
||
pos_terms.push_back(solver->MakeProd(vars[i], coefficients[i])->Var());
|
||
} else {
|
||
neg_terms.push_back(solver->MakeProd(vars[i], -coefficients[i])->Var());
|
||
}
|
||
}
|
||
if (negatives == 1) {
|
||
IntVar* const neg_term = solver->MakeSum(neg_terms[0], rhs)->Var();
|
||
return solver->MakeLessOrEqual(
|
||
solver->MakeSum(pos_terms)->Var(), neg_term);
|
||
} else if (positives == 1) {
|
||
IntVar* const pos_term = solver->MakeSum(pos_terms[0], -rhs)->Var();
|
||
return solver->MakeGreaterOrEqual(
|
||
solver->MakeSum(neg_terms)->Var(), pos_term);
|
||
} else {
|
||
if (rhs != 0) {
|
||
neg_terms.push_back(solver->MakeIntConst(rhs));
|
||
}
|
||
return solver->MakeLessOrEqual(
|
||
solver->MakeSum(pos_terms)->Var(),
|
||
solver->MakeSum(neg_terms)->Var());
|
||
}
|
||
} else if (positives == 1) {
|
||
IntVar* pos_term = NULL;
|
||
int64 rhs = upper_bound;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
rhs -= coefficients[i] * vars[i]->Min();
|
||
} else if (coefficients[i] > 0) {
|
||
pos_term = solver->MakeProd(vars[i], coefficients[i])->Var();
|
||
} else {
|
||
LOG(FATAL) << "Should not be here";
|
||
}
|
||
}
|
||
return solver->MakeLessOrEqual(pos_term, rhs);
|
||
} else if (negatives == 1) {
|
||
IntVar* neg_term = NULL;
|
||
int64 rhs = upper_bound;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
rhs -= coefficients[i] * vars[i]->Min();
|
||
} else if (coefficients[i] > 0) {
|
||
LOG(FATAL) << "Should not be here";
|
||
} else {
|
||
neg_term = solver->MakeProd(vars[i], -coefficients[i])->Var();
|
||
}
|
||
}
|
||
return solver->MakeGreaterOrEqual(neg_term, -rhs);
|
||
} else if (positives > 1) {
|
||
std::vector<IntVar*> pos_terms;
|
||
int64 rhs = upper_bound;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
rhs -= coefficients[i] * vars[i]->Min();
|
||
} else if (coefficients[i] > 0) {
|
||
pos_terms.push_back(solver->MakeProd(vars[i], coefficients[i])->Var());
|
||
} else {
|
||
LOG(FATAL) << "Should not be here";
|
||
}
|
||
}
|
||
return solver->MakeSumLessOrEqual(pos_terms, rhs);
|
||
} else if (negatives > 1) {
|
||
std::vector<IntVar*> neg_terms;
|
||
int64 rhs = upper_bound;
|
||
for (int i = 0; i < size; ++i) {
|
||
if (coefficients[i] == 0 || vars[i]->Bound()) {
|
||
rhs -= coefficients[i] * vars[i]->Min();
|
||
} else if (coefficients[i] > 0) {
|
||
LOG(FATAL) << "Should not be here";
|
||
} else {
|
||
neg_terms.push_back(solver->MakeProd(vars[i], -coefficients[i])->Var());
|
||
}
|
||
}
|
||
return solver->MakeSumGreaterOrEqual(neg_terms, -rhs);
|
||
}
|
||
std::vector<IntVar*> terms;
|
||
for (int i = 0; i < size; ++i) {
|
||
terms.push_back(solver->MakeProd(vars[i], coefficients[i])->Var());
|
||
}
|
||
return solver->MakeLessOrEqual(solver->MakeSum(terms), upper_bound);
|
||
}
|
||
} // namespace
|
||
|
||
Constraint* Solver::MakeScalProdLessOrEqual(const std::vector<IntVar*>& vars,
|
||
const std::vector<int64>& coefficients,
|
||
int64 cst) {
|
||
DCHECK_EQ(vars.size(), coefficients.size());
|
||
return MakeScalProdLessOrEqualFct<int64>(this,
|
||
vars.data(),
|
||
vars.size(),
|
||
coefficients.data(),
|
||
cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdLessOrEqual(const std::vector<IntVar*>& vars,
|
||
const std::vector<int>& coefficients,
|
||
int64 cst) {
|
||
DCHECK_EQ(vars.size(), coefficients.size());
|
||
return MakeScalProdLessOrEqualFct<int>(this,
|
||
vars.data(),
|
||
vars.size(),
|
||
coefficients.data(),
|
||
cst);
|
||
}
|
||
|
||
namespace {
|
||
template<class T> IntExpr* MakeScalProdFct(Solver* solver,
|
||
const std::vector<IntVar*>& pre_vars,
|
||
const std::vector<T>& pre_coefs) {
|
||
hash_map<const IntExpr*, int64> map;
|
||
ExprLinearizer lin(&map);
|
||
for (int i = 0; i < pre_vars.size(); ++i) {
|
||
lin.Visit(pre_vars[i], pre_coefs[i]);
|
||
}
|
||
const int64 constant = lin.Constant();
|
||
std::vector<IntVar*> vars;
|
||
std::vector<T> coefs;
|
||
for (ConstIter<hash_map<const IntExpr*, int64> > iter(map);
|
||
!iter.at_end();
|
||
++iter) {
|
||
vars.push_back(const_cast<IntExpr*>(iter->first)->Var());
|
||
coefs.push_back(iter->second);
|
||
}
|
||
if (constant != 0) {
|
||
vars.push_back(solver->MakeIntConst(1));
|
||
coefs.push_back(constant);
|
||
}
|
||
|
||
const int size = vars.size();
|
||
if (vars.empty() || AreAllNull<T>(coefs.data(), size)) {
|
||
return solver->MakeIntConst(0LL);
|
||
}
|
||
if (AreAllBoundOrNull(vars.data(), coefs.data(), size)) {
|
||
int64 cst = 0;
|
||
for (int i = 0; i < size; ++i) {
|
||
cst += vars[i]->Min() * coefs[i];
|
||
}
|
||
return solver->MakeIntConst(cst);
|
||
}
|
||
if (AreAllOnes(coefs.data(), size)) {
|
||
return solver->MakeSum(vars);
|
||
}
|
||
if (size == 1) {
|
||
return solver->MakeProd(vars[0], coefs[0]);
|
||
}
|
||
if (AreAllBooleans(vars.data(), size) && size > 2) {
|
||
if (AreAllPositive<T>(coefs.data(), size)) {
|
||
return solver->RegisterIntExpr(solver->RevAlloc(
|
||
new PositiveBooleanScalProd(
|
||
solver, vars.data(), size, coefs.data())));
|
||
} else {
|
||
// If some coefficients are non-positive, partition coefficients in two
|
||
// sets, one for the positive coefficients P and one for the negative
|
||
// ones N.
|
||
// Create two PositiveBooleanScalProd expressions, one on P (s1), the
|
||
// other on Opposite(N) (s2).
|
||
// The final expression is then s1 - s2.
|
||
// If P is empty, the expression is Opposite(s2).
|
||
std::vector<T> positive_coefs;
|
||
std::vector<T> negative_coefs;
|
||
std::vector<IntVar*> positive_coef_vars;
|
||
std::vector<IntVar*> negative_coef_vars;
|
||
for (int i = 0; i < size; ++i) {
|
||
const T coef = coefs[i];
|
||
if (coef > 0) {
|
||
positive_coefs.push_back(coef);
|
||
positive_coef_vars.push_back(vars[i]);
|
||
} else if (coef < 0) {
|
||
negative_coefs.push_back(-coef);
|
||
negative_coef_vars.push_back(vars[i]);
|
||
}
|
||
}
|
||
CHECK_GT(negative_coef_vars.size(), 0);
|
||
IntExpr* const negatives =
|
||
solver->RegisterIntExpr(solver->RevAlloc(
|
||
new PositiveBooleanScalProd(solver,
|
||
negative_coef_vars.data(),
|
||
negative_coef_vars.size(),
|
||
negative_coefs.data())));
|
||
if (!positive_coefs.empty()) {
|
||
IntExpr* const positives =
|
||
solver->RegisterIntExpr(solver->RevAlloc(
|
||
new PositiveBooleanScalProd(solver,
|
||
positive_coef_vars.data(),
|
||
positive_coef_vars.size(),
|
||
positive_coefs.data())));
|
||
// Cast to var to avoid slow propagation; all operations on the expr are
|
||
// O(n)!
|
||
return solver->MakeDifference(positives->Var(), negatives->Var());
|
||
} else {
|
||
return solver->MakeOpposite(negatives);
|
||
}
|
||
}
|
||
}
|
||
std::vector<IntVar*> terms;
|
||
for (int i = 0; i < size; ++i) {
|
||
terms.push_back(solver->MakeProd(vars[i], coefs[i])->Var());
|
||
}
|
||
return solver->MakeSum(terms);
|
||
}
|
||
} // namespace
|
||
|
||
IntExpr* Solver::MakeScalProd(const std::vector<IntVar*>& vars,
|
||
const std::vector<int64>& coefs) {
|
||
DCHECK_EQ(vars.size(), coefs.size());
|
||
return MakeScalProdFct<int64>(this, vars, coefs);
|
||
}
|
||
|
||
IntExpr* Solver::MakeScalProd(const std::vector<IntVar*>& vars,
|
||
const std::vector<int>& coefs) {
|
||
DCHECK_EQ(vars.size(), coefs.size());
|
||
return MakeScalProdFct<int>(this, vars, coefs);
|
||
}
|
||
} // namespace operations_research
|