2922 lines
86 KiB
C++
2922 lines
86 KiB
C++
// Copyright 2010-2011 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 "base/commandlineflags.h"
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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_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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// ---------- Base array classes used for code factorization ----------
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// ----- Array Constraint -----
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class ArrayConstraint : public Constraint {
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public:
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ArrayConstraint(Solver* const s,
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const IntVar* const * vars,
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int size,
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IntVar* const var)
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: Constraint(s), vars_(new IntVar*[size]), size_(size), var_(var) {
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CHECK_GT(size, 0);
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CHECK_NOTNULL(vars);
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memcpy(vars_.get(), vars, size_ * sizeof(*vars));
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}
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virtual ~ArrayConstraint() {}
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protected:
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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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DebugStringArray(vars_.get(), size_, ", ").c_str(),
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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_.get(),
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size_);
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visitor->VisitIntegerExpressionArgument(ModelVisitor::kTargetArgument,
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var_);
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visitor->EndVisitConstraint(name, this);
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}
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scoped_array<IntVar*> vars_;
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const int size_;
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IntVar* const var_;
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};
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// ----- ArrayExpr -----
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class ArrayExpr : public BaseIntExpr {
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public:
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ArrayExpr(Solver* const s, const IntVar* const* vars, int size)
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: BaseIntExpr(s), vars_(new IntVar*[size]), size_(size) {
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CHECK_GT(size, 0);
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CHECK_NOTNULL(vars);
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memcpy(vars_.get(), vars, size_ * sizeof(*vars));
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}
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virtual ~ArrayExpr() {}
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protected:
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string DebugStringInternal(const string& name) const {
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return StringPrintf("%s(%s)",
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name.c_str(),
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DebugStringArray(vars_.get(), size_, ", ").c_str());
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}
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void AcceptInternal(const string& name, ModelVisitor* const visitor) const {
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visitor->BeginVisitIntegerExpression(name, this);
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visitor->VisitIntegerVariableArrayArgument(ModelVisitor::kVarsArgument,
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vars_.get(),
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size_);
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visitor->EndVisitIntegerExpression(name, this);
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}
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scoped_array<IntVar*> vars_;
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const int size_;
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};
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// ----- Tree Array Constraint -----
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// Helper class
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class TreeArrayConstraint : public ArrayConstraint {
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public:
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TreeArrayConstraint(Solver* const solver,
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IntVar* const* vars,
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int size,
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IntVar* const sum_var)
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: ArrayConstraint(solver, vars, size, sum_var),
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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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// 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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const uint64 stamp = solver()->stamp();
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NodeInfo* const info = &tree_[depth][position];
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if (delta_min > 0) {
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if (stamp != info->min_stamp) {
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solver()->SaveValue(&info->node_min);
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info->min_stamp = stamp;
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}
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info->node_min += delta_min;
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}
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if (delta_max > 0) {
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if (stamp != info->max_stamp) {
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solver()->SaveValue(&info->node_max);
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info->max_stamp = stamp;
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}
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info->node_max -= delta_max;
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}
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}
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void InitLeaf(int position, int64 var_min, 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, int position, int64 node_min, int64 node_max) {
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NodeInfo* const info = &tree_[depth][position];
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info->node_min = node_min;
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info->min_stamp = 0;
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info->node_max = node_max;
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info->max_stamp= 0;
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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;
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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;
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}
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int64 RootMin() const {
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return root_node_->node_min;
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}
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int64 RootMax() const {
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return root_node_->node_max;
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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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private:
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struct NodeInfo {
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int64 node_min;
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int64 node_max;
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uint64 min_stamp;
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uint64 max_stamp;
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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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IntVar* const * vars,
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int size,
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IntVar* const sum_var)
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: TreeArrayConstraint(solver, vars, size, 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_ = MakeDelayedConstraintDemon0(solver(),
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this,
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&SumConstraint::SumChanged,
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"SumChanged");
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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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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 (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 (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, var_->Min(), 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 var_min = Min(depth + 1, i);
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const int64 var_max = Max(depth + 1, i);
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const int64 residual_min = sum_min - var_min;
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const int64 residual_max = sum_max - 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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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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// ---------- Min Array ----------
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// ----- Min Bool Array Ct -----
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// This constraint implements min(vars) == var. It is delayed such
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// that propagation only occurs when all variables have been touched.
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class MinBoolArrayCt : public ArrayConstraint {
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public:
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MinBoolArrayCt(Solver* const s, const IntVar* const * vars, int size,
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IntVar* var);
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virtual ~MinBoolArrayCt() {}
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virtual void Post();
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virtual void InitialPropagate();
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void Update(int index);
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void UpdateVar();
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virtual string DebugString() const;
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virtual void Accept(ModelVisitor* const visitor) const {
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AcceptInternal(ModelVisitor::kMinEqual, visitor);
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}
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private:
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SmallRevBitSet bits_;
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bool inhibited_;
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};
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MinBoolArrayCt::MinBoolArrayCt(Solver* const s,
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const IntVar* const * vars,
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int size,
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IntVar* var)
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: ArrayConstraint(s, vars, size, var), bits_(size), inhibited_(false) {}
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void MinBoolArrayCt::Post() {
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for (int i = 0; i < size_; ++i) {
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Demon* d = MakeConstraintDemon1(solver(),
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this,
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&MinBoolArrayCt::Update,
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"Update",
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i);
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vars_[i]->WhenRange(d);
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}
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Demon* uv = MakeConstraintDemon0(solver(),
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this,
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&MinBoolArrayCt::UpdateVar,
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"UpdateVar");
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var_->WhenRange(uv);
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}
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void MinBoolArrayCt::InitialPropagate() {
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if (var_->Min() == 1LL) {
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for (int i = 0; i < size_; ++i) {
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vars_[i]->SetMin(1LL);
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}
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solver()->SaveAndSetValue(&inhibited_, true);
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} else {
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for (int i = 0; i < size_; ++i) {
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IntVar* const var = vars_[i];
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if (var->Max() == 0LL) {
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var_->SetMax(0LL);
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solver()->SaveAndSetValue(&inhibited_, true);
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return;
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}
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if (var->Min() == 0LL) {
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bits_.SetToOne(solver(), i);
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}
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}
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if (bits_.IsCardinalityZero()) {
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var_->SetValue(1LL);
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solver()->SaveAndSetValue(&inhibited_, true);
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} else if (var_->Max() == 0LL && bits_.IsCardinalityOne()) {
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vars_[bits_.GetFirstOne()]->SetValue(0LL);
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solver()->SaveAndSetValue(&inhibited_, true);
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}
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}
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}
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void MinBoolArrayCt::Update(int index) {
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if (!inhibited_) {
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if (vars_[index]->Max() == 0LL) { // Bound to 0.
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var_->SetValue(0LL);
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solver()->SaveAndSetValue(&inhibited_, true);
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} else {
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bits_.SetToZero(solver(), index);
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if (bits_.IsCardinalityZero()) {
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var_->SetValue(1LL);
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solver()->SaveAndSetValue(&inhibited_, true);
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} else if (var_->Max() == 0LL && bits_.IsCardinalityOne()) {
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vars_[bits_.GetFirstOne()]->SetValue(0LL);
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solver()->SaveAndSetValue(&inhibited_, true);
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}
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}
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}
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}
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void MinBoolArrayCt::UpdateVar() {
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if (!inhibited_) {
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if (var_->Min() == 1LL) {
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for (int i = 0; i < size_; ++i) {
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vars_[i]->SetMin(1LL);
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}
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solver()->SaveAndSetValue(&inhibited_, true);
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} else {
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if (bits_.IsCardinalityOne()) {
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vars_[bits_.GetFirstOne()]->SetValue(0LL);
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solver()->SaveAndSetValue(&inhibited_, true);
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}
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}
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}
|
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}
|
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string MinBoolArrayCt::DebugString() const {
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return DebugStringInternal("MinBoolArrayCt");
|
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}
|
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|
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// ----- MinBoolArray -----
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||
|
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class MinBoolArray : public ArrayExpr {
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public:
|
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// This constructor will copy the array. The caller can safely delete the
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// exprs array himself
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MinBoolArray(Solver* const s, const IntVar* const* exprs, int size);
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virtual ~MinBoolArray();
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virtual int64 Min() const;
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virtual void SetMin(int64 m);
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virtual int64 Max() const;
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virtual void SetMax(int64 m);
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virtual string DebugString() const;
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||
virtual void WhenRange(Demon* d);
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virtual IntVar* CastToVar() {
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Solver* const s = solver();
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int64 vmin = 0LL;
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int64 vmax = 0LL;
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Range(&vmin, &vmax);
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IntVar* var = solver()->MakeIntVar(vmin, vmax);
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AddDelegateName("Var", var);
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Constraint* const ct =
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s->RevAlloc(new MinBoolArrayCt(s, vars_.get(), size_, var));
|
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s->AddDelegateConstraint(ct);
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return var;
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}
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virtual void Accept(ModelVisitor* const visitor) const {
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AcceptInternal(ModelVisitor::kMin, visitor);
|
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}
|
||
};
|
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|
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MinBoolArray::~MinBoolArray() {}
|
||
|
||
MinBoolArray::MinBoolArray(Solver* const s, const IntVar* const* vars, int size)
|
||
: ArrayExpr(s, vars, size) {}
|
||
|
||
int64 MinBoolArray::Min() const {
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 vmin = vars_[i]->Min();
|
||
if (vmin == 0LL) {
|
||
return 0LL;
|
||
}
|
||
}
|
||
return 1LL;
|
||
}
|
||
|
||
void MinBoolArray::SetMin(int64 m) {
|
||
if (m <= 0) {
|
||
return;
|
||
}
|
||
if (m > 1) {
|
||
solver()->Fail();
|
||
}
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->SetMin(1LL);
|
||
}
|
||
}
|
||
|
||
int64 MinBoolArray::Max() const {
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 vmax = vars_[i]->Max();
|
||
if (vmax == 0LL) {
|
||
return 0LL;
|
||
}
|
||
}
|
||
return 1LL;
|
||
}
|
||
|
||
void MinBoolArray::SetMax(int64 m) {
|
||
if (m < 0) {
|
||
solver()->Fail();
|
||
} else if (m >= 1) {
|
||
return;
|
||
}
|
||
DCHECK_EQ(m, 0LL);
|
||
int active = 0;
|
||
int curr = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Min() == 0LL) {
|
||
active++;
|
||
curr = i;
|
||
}
|
||
}
|
||
if (active == 0) {
|
||
solver()->Fail();
|
||
}
|
||
if (active == 1) {
|
||
vars_[curr]->SetMax(0LL);
|
||
}
|
||
}
|
||
|
||
string MinBoolArray::DebugString() const {
|
||
return DebugStringInternal("MinBoolArray");
|
||
}
|
||
|
||
void MinBoolArray::WhenRange(Demon* d) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->WhenRange(d);
|
||
}
|
||
}
|
||
|
||
// ----- Min Array Ct -----
|
||
|
||
// This constraint implements min(vars) == var. It is delayed such
|
||
// that propagation only occurs when all variables have been touched.
|
||
class MinArrayCt : public ArrayConstraint {
|
||
public:
|
||
MinArrayCt(Solver* const s, const IntVar* const * vars, int size,
|
||
IntVar* var);
|
||
virtual ~MinArrayCt() {}
|
||
|
||
virtual void Post();
|
||
virtual void InitialPropagate();
|
||
|
||
void Update(int index);
|
||
void UpdateVar();
|
||
|
||
virtual string DebugString() const;
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
AcceptInternal(ModelVisitor::kMinEqual, visitor);
|
||
}
|
||
|
||
private:
|
||
Rev<int> min_support_;
|
||
};
|
||
|
||
MinArrayCt::MinArrayCt(Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size,
|
||
IntVar* var)
|
||
: ArrayConstraint(s, vars, size, var), min_support_(0) {}
|
||
|
||
void MinArrayCt::Post() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
Demon* d = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&MinArrayCt::Update,
|
||
"Update",
|
||
i);
|
||
vars_[i]->WhenRange(d);
|
||
}
|
||
Demon* uv = MakeConstraintDemon0(solver(),
|
||
this,
|
||
&MinArrayCt::UpdateVar,
|
||
"UpdateVar");
|
||
var_->WhenRange(uv);
|
||
}
|
||
|
||
void MinArrayCt::InitialPropagate() {
|
||
int64 vmin = var_->Min();
|
||
int64 vmax = var_->Max();
|
||
int64 cmin = kint64max;
|
||
int64 cmax = kint64max;
|
||
int min_support = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
IntVar* const var = vars_[i];
|
||
var->SetMin(vmin);
|
||
const int64 tmin = var->Min();
|
||
const int64 tmax = var->Max();
|
||
if (tmin < cmin) {
|
||
cmin = tmin;
|
||
min_support = i;
|
||
}
|
||
if (tmax < cmax) {
|
||
cmax = tmax;
|
||
}
|
||
}
|
||
min_support_.SetValue(solver(), min_support);
|
||
var_->SetRange(cmin, cmax);
|
||
vmin = var_->Min();
|
||
vmax = var_->Max();
|
||
int active = 0;
|
||
int curr = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Min() <= vmax) {
|
||
if (active++ >= 1) {
|
||
return;
|
||
}
|
||
curr = i;
|
||
}
|
||
}
|
||
if (active == 0) {
|
||
solver()->Fail();
|
||
}
|
||
if (active == 1) {
|
||
vars_[curr]->SetMax(vmax);
|
||
}
|
||
}
|
||
|
||
void MinArrayCt::Update(int index) {
|
||
IntVar* const modified = vars_[index];
|
||
if (modified->OldMax() != modified->Max()) {
|
||
var_->SetMax(modified->Max());
|
||
}
|
||
if (index == min_support_.Value() && modified->OldMin() != modified->Min()) {
|
||
// TODO(user) : can we merge this code with above into
|
||
// ComputeMinSupport?
|
||
int64 cmin = kint64max;
|
||
int min_support = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 tmin = vars_[i]->Min();
|
||
if (tmin < cmin) {
|
||
cmin = tmin;
|
||
min_support = i;
|
||
}
|
||
}
|
||
min_support_.SetValue(solver(), min_support);
|
||
var_->SetMin(cmin);
|
||
}
|
||
}
|
||
|
||
void MinArrayCt::UpdateVar() {
|
||
const int64 vmin = var_->Min();
|
||
if (vmin != var_->OldMin()) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->SetMin(vmin);
|
||
}
|
||
}
|
||
const int64 vmax = var_->Max();
|
||
if (vmax != var_->OldMax()) {
|
||
int active = 0;
|
||
int curr = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Min() <= vmax) {
|
||
if (active++ >= 1) {
|
||
return;
|
||
}
|
||
curr = i;
|
||
}
|
||
}
|
||
if (active == 0) {
|
||
solver()->Fail();
|
||
}
|
||
if (active == 1) {
|
||
vars_[curr]->SetMax(vmax);
|
||
}
|
||
}
|
||
}
|
||
|
||
string MinArrayCt::DebugString() const {
|
||
return DebugStringInternal("MinArrayCt");
|
||
}
|
||
|
||
// Array Min: the min of all the elements. More efficient that using just
|
||
// binary MinIntExpr operators when the array grows
|
||
class MinArray : public ArrayExpr {
|
||
public:
|
||
// this constructor will copy the array. The caller can safely delete the
|
||
// exprs array himself
|
||
MinArray(Solver* const s, const IntVar* const* exprs, int size);
|
||
virtual ~MinArray();
|
||
|
||
virtual int64 Min() const;
|
||
virtual void SetMin(int64 m);
|
||
virtual int64 Max() const;
|
||
virtual void SetMax(int64 m);
|
||
virtual string DebugString() const;
|
||
virtual void WhenRange(Demon* d);
|
||
virtual IntVar* CastToVar() {
|
||
Solver* const s = solver();
|
||
int64 vmin = 0LL;
|
||
int64 vmax = 0LL;
|
||
Range(&vmin, &vmax);
|
||
IntVar* var = solver()->MakeIntVar(vmin, vmax);
|
||
AddDelegateName("Var", var);
|
||
Constraint* const ct =
|
||
s->RevAlloc(new MinArrayCt(s, vars_.get(), size_, var));
|
||
s->AddDelegateConstraint(ct);
|
||
return var;
|
||
}
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
AcceptInternal(ModelVisitor::kMin, visitor);
|
||
}
|
||
};
|
||
|
||
MinArray::~MinArray() {}
|
||
|
||
MinArray::MinArray(Solver* const s, const IntVar* const* vars, int size)
|
||
: ArrayExpr(s, vars, size) {}
|
||
|
||
int64 MinArray::Min() const {
|
||
int64 min = kint64max;
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 vmin = vars_[i]->Min();
|
||
if (min > vmin) {
|
||
min = vmin;
|
||
}
|
||
}
|
||
return min;
|
||
}
|
||
|
||
void MinArray::SetMin(int64 m) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->SetMin(m);
|
||
}
|
||
}
|
||
|
||
int64 MinArray::Max() const {
|
||
int64 max = kint64max;
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 vmax = vars_[i]->Max();
|
||
if (max > vmax) {
|
||
max = vmax;
|
||
}
|
||
}
|
||
return max;
|
||
}
|
||
|
||
void MinArray::SetMax(int64 m) {
|
||
int active = 0;
|
||
int curr = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Min() <= m) {
|
||
if (active++ >= 1) {
|
||
return;
|
||
}
|
||
curr = i;
|
||
}
|
||
}
|
||
if (active == 0) {
|
||
solver()->Fail();
|
||
}
|
||
if (active == 1) {
|
||
vars_[curr]->SetMax(m);
|
||
}
|
||
}
|
||
|
||
string MinArray::DebugString() const {
|
||
return DebugStringInternal("MinArray");
|
||
}
|
||
|
||
void MinArray::WhenRange(Demon* d) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->WhenRange(d);
|
||
}
|
||
}
|
||
|
||
// ---------- Max Array ----------
|
||
|
||
// ----- Max Array Ct -----
|
||
|
||
// This constraint implements max(vars) == var.
|
||
class MaxArrayCt : public ArrayConstraint {
|
||
public:
|
||
MaxArrayCt(Solver* const s, const IntVar* const * vars, int size,
|
||
IntVar* var);
|
||
virtual ~MaxArrayCt() {}
|
||
|
||
virtual void Post();
|
||
virtual void InitialPropagate();
|
||
|
||
void Update(int index);
|
||
void UpdateVar();
|
||
|
||
virtual string DebugString() const;
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
AcceptInternal(ModelVisitor::kMaxEqual, visitor);
|
||
}
|
||
|
||
private:
|
||
Rev<int> max_support_;
|
||
};
|
||
|
||
MaxArrayCt::MaxArrayCt(Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size,
|
||
IntVar* var)
|
||
: ArrayConstraint(s, vars, size, var), max_support_(0) {}
|
||
|
||
void MaxArrayCt::Post() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
Demon* d = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&MaxArrayCt::Update,
|
||
"Update",
|
||
i);
|
||
vars_[i]->WhenRange(d);
|
||
}
|
||
Demon* uv = MakeConstraintDemon0(solver(),
|
||
this,
|
||
&MaxArrayCt::UpdateVar,
|
||
"UpdateVar");
|
||
var_->WhenRange(uv);
|
||
}
|
||
|
||
void MaxArrayCt::InitialPropagate() {
|
||
int64 vmin = var_->Min();
|
||
int64 vmax = var_->Max();
|
||
int64 cmin = kint64min;
|
||
int64 cmax = kint64min;
|
||
int max_support = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
IntVar* const var = vars_[i];
|
||
var->SetMax(vmax);
|
||
const int64 tmin = var->Min();
|
||
const int64 tmax = var->Max();
|
||
if (tmin > cmin) {
|
||
cmin = tmin;
|
||
}
|
||
if (tmax > cmax) {
|
||
cmax = tmax;
|
||
max_support = i;
|
||
}
|
||
}
|
||
max_support_.SetValue(solver(), max_support);
|
||
var_->SetRange(cmin, cmax);
|
||
vmin = var_->Min();
|
||
vmax = var_->Max();
|
||
int active = 0;
|
||
int curr = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Max() >= vmin) {
|
||
if (active++ >= 1) {
|
||
return;
|
||
}
|
||
curr = i;
|
||
}
|
||
}
|
||
if (active == 0) {
|
||
solver()->Fail();
|
||
}
|
||
if (active == 1) {
|
||
vars_[curr]->SetMin(vmin);
|
||
}
|
||
}
|
||
|
||
void MaxArrayCt::Update(int index) {
|
||
IntVar* const modified = vars_[index];
|
||
if (modified->OldMin() != modified->Min()) {
|
||
var_->SetMin(modified->Min());
|
||
}
|
||
const int64 oldmax = modified->OldMax();
|
||
if (index == max_support_.Value() && oldmax != modified->Max()) {
|
||
// TODO(user) : can we merge this code with above into
|
||
// ComputeMaxSupport?
|
||
int64 cmax = kint64min;
|
||
int max_support = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 tmax = vars_[i]->Max();
|
||
if (tmax > cmax) {
|
||
cmax = tmax;
|
||
max_support = i;
|
||
}
|
||
}
|
||
max_support_.SetValue(solver(), max_support);
|
||
var_->SetMax(cmax);
|
||
}
|
||
}
|
||
|
||
void MaxArrayCt::UpdateVar() {
|
||
const int64 vmax = var_->Max();
|
||
if (vmax != var_->OldMax()) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->SetMax(vmax);
|
||
}
|
||
}
|
||
const int64 vmin = var_->Min();
|
||
if (vmin != var_->OldMin()) {
|
||
int active = 0;
|
||
int curr = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Max() >= vmin) {
|
||
if (active++ >= 1) {
|
||
return;
|
||
}
|
||
curr = i;
|
||
}
|
||
}
|
||
if (active == 0) {
|
||
solver()->Fail();
|
||
}
|
||
if (active == 1) {
|
||
vars_[curr]->SetMin(vmin);
|
||
}
|
||
}
|
||
}
|
||
|
||
string MaxArrayCt::DebugString() const {
|
||
return DebugStringInternal("MaxArrayCt");
|
||
}
|
||
|
||
// Array Max: the max of all the elements. More efficient that using just
|
||
// binary MaxIntExpr operators when the array grows
|
||
class MaxArray : public ArrayExpr {
|
||
public:
|
||
// this constructor will copy the array. The caller can safely delete the
|
||
// exprs array himself
|
||
MaxArray(Solver* const s, const IntVar* const* exprs, int size);
|
||
virtual ~MaxArray();
|
||
|
||
virtual int64 Min() const;
|
||
virtual void SetMin(int64 m);
|
||
virtual int64 Max() const;
|
||
virtual void SetMax(int64 m);
|
||
virtual string DebugString() const;
|
||
virtual void WhenRange(Demon* d);
|
||
virtual IntVar* CastToVar() {
|
||
Solver* const s = solver();
|
||
int64 vmin = Min();
|
||
int64 vmax = Max();
|
||
IntVar* var = solver()->MakeIntVar(vmin, vmax);
|
||
AddDelegateName("Var", var);
|
||
Constraint* const ct =
|
||
s->RevAlloc(new MaxArrayCt(s, vars_.get(), size_, var));
|
||
s->AddDelegateConstraint(ct);
|
||
return var;
|
||
}
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
AcceptInternal(ModelVisitor::kMax, visitor);
|
||
}
|
||
};
|
||
|
||
MaxArray::~MaxArray() {}
|
||
|
||
MaxArray::MaxArray(Solver* const s, const IntVar* const* vars, int size)
|
||
: ArrayExpr(s, vars, size) {}
|
||
|
||
int64 MaxArray::Min() const {
|
||
int64 min = kint64min;
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 vmin = vars_[i]->Min();
|
||
if (min < vmin) {
|
||
min = vmin;
|
||
}
|
||
}
|
||
return min;
|
||
}
|
||
|
||
void MaxArray::SetMin(int64 m) {
|
||
int active = 0;
|
||
int curr = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Max() >= m) {
|
||
active++;
|
||
curr = i;
|
||
}
|
||
}
|
||
if (active == 0) {
|
||
solver()->Fail();
|
||
}
|
||
if (active == 1) {
|
||
vars_[curr]->SetMin(m);
|
||
}
|
||
}
|
||
|
||
int64 MaxArray::Max() const {
|
||
int64 max = kint64min;
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 vmax = vars_[i]->Max();
|
||
if (max < vmax) {
|
||
max = vmax;
|
||
}
|
||
}
|
||
return max;
|
||
}
|
||
|
||
void MaxArray::SetMax(int64 m) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->SetMax(m);
|
||
}
|
||
}
|
||
|
||
string MaxArray::DebugString() const {
|
||
return DebugStringInternal("MaxArray");
|
||
}
|
||
|
||
void MaxArray::WhenRange(Demon* d) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->WhenRange(d);
|
||
}
|
||
}
|
||
|
||
// ----- Max Bool Array Ct -----
|
||
|
||
// This constraint implements max(vars) == var. It is delayed such
|
||
// that propagation only occurs when all variables have been touched.
|
||
class MaxBoolArrayCt : public ArrayConstraint {
|
||
public:
|
||
MaxBoolArrayCt(Solver* const s, const IntVar* const * vars, int size,
|
||
IntVar* var);
|
||
virtual ~MaxBoolArrayCt() {}
|
||
|
||
virtual void Post();
|
||
virtual void InitialPropagate();
|
||
|
||
void Update(int index);
|
||
void UpdateVar();
|
||
|
||
virtual string DebugString() const;
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
AcceptInternal(ModelVisitor::kMaxEqual, visitor);
|
||
}
|
||
|
||
private:
|
||
SmallRevBitSet bits_;
|
||
bool inhibited_;
|
||
};
|
||
|
||
MaxBoolArrayCt::MaxBoolArrayCt(Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size,
|
||
IntVar* var)
|
||
: ArrayConstraint(s, vars, size, var), bits_(size), inhibited_(false) {}
|
||
|
||
void MaxBoolArrayCt::Post() {
|
||
for (int i = 0; i < size_; ++i) {
|
||
Demon* d = MakeConstraintDemon1(solver(),
|
||
this,
|
||
&MaxBoolArrayCt::Update,
|
||
"Update",
|
||
i);
|
||
vars_[i]->WhenRange(d);
|
||
}
|
||
|
||
Demon* uv = MakeConstraintDemon0(solver(),
|
||
this,
|
||
&MaxBoolArrayCt::UpdateVar,
|
||
"UpdateVar");
|
||
var_->WhenRange(uv);
|
||
}
|
||
|
||
void MaxBoolArrayCt::InitialPropagate() {
|
||
if (var_->Max() == 0) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->SetMax(0LL);
|
||
}
|
||
solver()->SaveAndSetValue(&inhibited_, true);
|
||
} else {
|
||
for (int i = 0; i < size_; ++i) {
|
||
IntVar* const var = vars_[i];
|
||
if (var->Min() == 1LL) {
|
||
var_->SetMin(1LL);
|
||
solver()->SaveAndSetValue(&inhibited_, true);
|
||
return;
|
||
}
|
||
if (var->Max() == 1LL) {
|
||
bits_.SetToOne(solver(), i);
|
||
}
|
||
}
|
||
if (bits_.IsCardinalityZero()) {
|
||
var_->SetValue(0LL);
|
||
solver()->SaveAndSetValue(&inhibited_, true);
|
||
} else if (var_->Min() == 1LL && bits_.IsCardinalityOne()) {
|
||
vars_[bits_.GetFirstOne()]->SetValue(1LL);
|
||
solver()->SaveAndSetValue(&inhibited_, true);
|
||
}
|
||
}
|
||
}
|
||
|
||
void MaxBoolArrayCt::Update(int index) {
|
||
if (!inhibited_) {
|
||
if (vars_[index]->Min() == 1LL) { // Bound to 1.
|
||
var_->SetValue(1LL);
|
||
solver()->SaveAndSetValue(&inhibited_, true);
|
||
} else {
|
||
bits_.SetToZero(solver(), index);
|
||
if (bits_.IsCardinalityZero()) {
|
||
var_->SetValue(0LL);
|
||
solver()->SaveAndSetValue(&inhibited_, true);
|
||
} else if (var_->Min() == 1LL && bits_.IsCardinalityOne()) {
|
||
vars_[bits_.GetFirstOne()]->SetValue(1LL);
|
||
solver()->SaveAndSetValue(&inhibited_, true);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
void MaxBoolArrayCt::UpdateVar() {
|
||
if (!inhibited_) {
|
||
if (var_->Max() == 0) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->SetMax(0LL);
|
||
}
|
||
solver()->SaveAndSetValue(&inhibited_, true);
|
||
} else {
|
||
if (bits_.IsCardinalityOne()) {
|
||
vars_[bits_.GetFirstOne()]->SetValue(1LL);
|
||
solver()->SaveAndSetValue(&inhibited_, true);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
string MaxBoolArrayCt::DebugString() const {
|
||
return DebugStringInternal("MaxBoolArrayCt");
|
||
}
|
||
|
||
// ----- MaxBoolArray -----
|
||
|
||
class MaxBoolArray : public ArrayExpr {
|
||
public:
|
||
// this constructor will copy the array. The caller can safely delete the
|
||
// exprs array himself
|
||
MaxBoolArray(Solver* const s, const IntVar* const* exprs, int size);
|
||
virtual ~MaxBoolArray();
|
||
|
||
virtual int64 Min() const;
|
||
virtual void SetMin(int64 m);
|
||
virtual int64 Max() const;
|
||
virtual void SetMax(int64 m);
|
||
virtual string DebugString() const;
|
||
virtual void WhenRange(Demon* d);
|
||
virtual IntVar* CastToVar() {
|
||
Solver* const s = solver();
|
||
int64 vmin = Min();
|
||
int64 vmax = Max();
|
||
IntVar* var = solver()->MakeIntVar(vmin, vmax);
|
||
AddDelegateName("Var", var);
|
||
Constraint* const ct =
|
||
s->RevAlloc(new MaxBoolArrayCt(s, vars_.get(), size_, var));
|
||
s->AddDelegateConstraint(ct);
|
||
return var;
|
||
}
|
||
|
||
virtual void Accept(ModelVisitor* const visitor) const {
|
||
AcceptInternal(ModelVisitor::kMax, visitor);
|
||
}
|
||
};
|
||
|
||
MaxBoolArray::~MaxBoolArray() {}
|
||
|
||
MaxBoolArray::MaxBoolArray(Solver* const s, const IntVar* const* vars, int size)
|
||
: ArrayExpr(s, vars, size) {}
|
||
|
||
int64 MaxBoolArray::Min() const {
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 vmin = vars_[i]->Min();
|
||
if (vmin == 1LL) {
|
||
return 1LL;
|
||
}
|
||
}
|
||
return 0LL;
|
||
}
|
||
|
||
void MaxBoolArray::SetMin(int64 m) {
|
||
if (m > 1) {
|
||
solver()->Fail();
|
||
} else if (m <= 0) {
|
||
return;
|
||
}
|
||
DCHECK_EQ(m, 1LL);
|
||
int active = 0;
|
||
int curr = -1;
|
||
for (int i = 0; i < size_; ++i) {
|
||
if (vars_[i]->Max() == 1LL) {
|
||
active++;
|
||
curr = i;
|
||
}
|
||
}
|
||
if (active == 0) {
|
||
solver()->Fail();
|
||
}
|
||
if (active == 1) {
|
||
vars_[curr]->SetMin(1LL);
|
||
}
|
||
}
|
||
|
||
int64 MaxBoolArray::Max() const {
|
||
for (int i = 0; i < size_; ++i) {
|
||
const int64 vmax = vars_[i]->Max();
|
||
if (vmax == 1LL) {
|
||
return 1LL;
|
||
}
|
||
}
|
||
return 0LL;
|
||
}
|
||
|
||
void MaxBoolArray::SetMax(int64 m) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->SetMax(m);
|
||
}
|
||
}
|
||
|
||
string MaxBoolArray::DebugString() const {
|
||
return DebugStringInternal("MaxBoolArray");
|
||
}
|
||
|
||
void MaxBoolArray::WhenRange(Demon* d) {
|
||
for (int i = 0; i < size_; ++i) {
|
||
vars_[i]->WhenRange(d);
|
||
}
|
||
}
|
||
|
||
// ----- Builders -----
|
||
|
||
void ScanArray(IntVar* const* vars, int size, int* bound,
|
||
int64* amin, int64* amax, int64* min_max, int64* max_min) {
|
||
*amin = kint64max; // Max of the array.
|
||
*min_max = kint64max; // Smallest max in the array.
|
||
*max_min = kint64min; // Biggest min in the array.
|
||
*amax = kint64min; // Min of the array.
|
||
*bound = 0;
|
||
for (int i = 0; i < size; ++i) {
|
||
const int64 vmin = vars[i]->Min();
|
||
const int64 vmax = vars[i]->Max();
|
||
if (vmin < *amin) {
|
||
*amin = vmin;
|
||
}
|
||
if (vmax > *amax) {
|
||
*amax = vmax;
|
||
}
|
||
if (vmax < *min_max) {
|
||
*min_max = vmax;
|
||
}
|
||
if (vmin > *max_min) {
|
||
*max_min = vmin;
|
||
}
|
||
if (vmin == vmax) {
|
||
(*bound)++;
|
||
}
|
||
}
|
||
}
|
||
|
||
IntExpr* BuildMinArray(Solver* const s, IntVar* const* vars, int size) {
|
||
int64 amin = 0, amax = 0, min_max = 0, max_min = 0;
|
||
int bound = 0;
|
||
ScanArray(vars, size, &bound, &amin, &amax, &min_max, &max_min);
|
||
if (bound == size || amin == min_max) { // Bound min(array)
|
||
return s->MakeIntConst(amin);
|
||
}
|
||
if (amin == 0 && amax == 1) {
|
||
return s->RevAlloc(new MinBoolArray(s, vars, size));
|
||
}
|
||
return s->RevAlloc(new MinArray(s, vars, size));
|
||
}
|
||
|
||
IntExpr* BuildMaxArray(Solver* const s, IntVar* const* vars, int size) {
|
||
int64 amin = 0, amax = 0, min_max = 0, max_min = 0;
|
||
int bound = 0;
|
||
ScanArray(vars, size, &bound, &amin, &amax, &min_max, &max_min);
|
||
if (bound == size || amax == max_min) { // Bound max(array)
|
||
return s->MakeIntConst(amax);
|
||
}
|
||
if (amin == 0 && amax == 1) {
|
||
return s->RevAlloc(new MaxBoolArray(s, vars, size));
|
||
}
|
||
return s->RevAlloc(new MaxArray(s, vars, size));
|
||
}
|
||
|
||
enum BuildOp { MIN_OP, MAX_OP };
|
||
|
||
IntExpr* BuildLogSplitArray(Solver* const s,
|
||
IntVar* const* vars,
|
||
int size,
|
||
BuildOp op) {
|
||
const int split_size = s->parameters().array_split_size;
|
||
if (size == 0) {
|
||
return s->MakeIntConst(0LL);
|
||
} else if (size == 1) {
|
||
return vars[0];
|
||
} else if (size == 2) {
|
||
switch (op) {
|
||
case MIN_OP:
|
||
return s->MakeMin(vars[0], vars[1]);
|
||
case MAX_OP:
|
||
return s->MakeMax(vars[0], vars[1]);
|
||
};
|
||
} else if (size > split_size) {
|
||
const int nb_blocks = (size - 1) / split_size + 1;
|
||
const int block_size = (size + nb_blocks - 1) / nb_blocks;
|
||
std::vector<IntVar*> top_vector;
|
||
int start = 0;
|
||
while (start < size) {
|
||
int real_size = (start + block_size > size ? size - start : block_size);
|
||
IntVar* intermediate = NULL;
|
||
switch (op) {
|
||
case MIN_OP:
|
||
intermediate = s->MakeMin(vars + start, real_size)->Var();
|
||
break;
|
||
case MAX_OP:
|
||
intermediate = s->MakeMax(vars + start, real_size)->Var();
|
||
break;
|
||
}
|
||
top_vector.push_back(intermediate);
|
||
start += real_size;
|
||
}
|
||
switch (op) {
|
||
case MIN_OP:
|
||
return s->MakeMin(top_vector);
|
||
case MAX_OP:
|
||
return s->MakeMax(top_vector);
|
||
};
|
||
} else {
|
||
for (int i = 0; i < size; ++i) {
|
||
CHECK_EQ(s, vars[i]->solver());
|
||
}
|
||
switch (op) {
|
||
case MIN_OP:
|
||
return BuildMinArray(s, vars, size);
|
||
case MAX_OP:
|
||
return BuildMaxArray(s, vars, size);
|
||
};
|
||
}
|
||
LOG(FATAL) << "Unknown operator";
|
||
return NULL;
|
||
}
|
||
|
||
IntExpr* BuildLogSplitArray(Solver* const s,
|
||
const std::vector<IntVar*>& vars,
|
||
BuildOp op) {
|
||
return BuildLogSplitArray(s, vars.data(), vars.size(), op);
|
||
}
|
||
} // namespace
|
||
|
||
IntExpr* Solver::MakeSum(const std::vector<IntVar*>& vars) {
|
||
return MakeSum(vars.data(), vars.size());
|
||
}
|
||
|
||
IntExpr* Solver::MakeSum(IntVar* const* vars, int 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 {
|
||
int64 sum_min = 0;
|
||
int64 sum_max = 0;
|
||
for (int i = 0; i < size; ++i) {
|
||
sum_min += vars[i]->Min();
|
||
sum_max += vars[i]->Max();
|
||
}
|
||
IntVar* const sum_var = MakeIntVar(sum_min, sum_max);
|
||
AddConstraint(RevAlloc(new SumConstraint(this, vars, size, sum_var)));
|
||
return sum_var;
|
||
}
|
||
}
|
||
|
||
IntExpr* Solver::MakeMin(const std::vector<IntVar*>& vars) {
|
||
return BuildLogSplitArray(this, vars, MIN_OP);
|
||
}
|
||
|
||
IntExpr* Solver::MakeMin(IntVar* const* vars, int size) {
|
||
return BuildLogSplitArray(this, vars, size, MIN_OP);
|
||
}
|
||
|
||
IntExpr* Solver::MakeMax(const std::vector<IntVar*>& vars) {
|
||
return BuildLogSplitArray(this, vars, MAX_OP);
|
||
}
|
||
|
||
IntExpr* Solver::MakeMax(IntVar* const* vars, int size) {
|
||
return BuildLogSplitArray(this, vars, size, MAX_OP);
|
||
}
|
||
|
||
// ---------- Specialized cases ----------
|
||
|
||
namespace {
|
||
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 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 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), inactive_(false) {
|
||
CHECK_GT(size_, 0);
|
||
CHECK(vars != NULL);
|
||
memcpy(vars_.get(), vars, size_ * sizeof(*vars));
|
||
}
|
||
virtual ~BaseSumBooleanConstraint() {}
|
||
protected:
|
||
string DebugStringInternal(const string& name) const;
|
||
|
||
scoped_array<IntVar*> vars_;
|
||
int size_;
|
||
int 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_) {
|
||
DCHECK(vars_[index]->Bound());
|
||
if (vars_[index]->Min() == 1) {
|
||
PushAllToZeroExcept(index);
|
||
}
|
||
}
|
||
}
|
||
|
||
void PushAllToZeroExcept(int index) {
|
||
solver()->SaveAndSetValue(&inactive_, 1);
|
||
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) {
|
||
solver()->SaveAndSetValue(&inactive_, 1);
|
||
return;
|
||
}
|
||
if (var->Max() == 1LL) {
|
||
bits_.SetToOne(solver(), i);
|
||
}
|
||
}
|
||
if (bits_.IsCardinalityZero()) {
|
||
solver()->Fail();
|
||
} else if (bits_.IsCardinalityOne()) {
|
||
vars_[bits_.GetFirstBit(0)]->SetValue(1LL);
|
||
solver()->SaveAndSetValue(&inactive_, 1);
|
||
}
|
||
}
|
||
|
||
void SumBooleanGreaterOrEqualToOne::Update(int index) {
|
||
if (!inactive_) {
|
||
if (vars_[index]->Min() == 1LL) { // Bound to 1.
|
||
solver()->SaveAndSetValue(&inactive_, 1);
|
||
} else {
|
||
bits_.SetToZero(solver(), index);
|
||
if (bits_.IsCardinalityZero()) {
|
||
solver()->Fail();
|
||
} else if (bits_.IsCardinalityOne()) {
|
||
vars_[bits_.GetFirstBit(0)]->SetValue(1LL);
|
||
solver()->SaveAndSetValue(&inactive_, 1);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
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);
|
||
solver()->SaveAndSetValue(&inactive_, 1);
|
||
} else {
|
||
solver()->SaveAndSetValue(&active_vars_, max1);
|
||
}
|
||
}
|
||
|
||
void Update(int index) {
|
||
if (!inactive_) {
|
||
DCHECK(vars_[index]->Bound());
|
||
const int64 value = vars_[index]->Min(); // Faster than Value().
|
||
if (value == 0) {
|
||
solver()->SaveAndAdd(&active_vars_, -1);
|
||
DCHECK_GE(active_vars_, 0);
|
||
if (active_vars_ == 0) {
|
||
solver()->Fail();
|
||
} else if (active_vars_ == 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) {
|
||
solver()->SaveAndSetValue(&inactive_, 1);
|
||
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:
|
||
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 {
|
||
solver()->SaveAndSetValue(&num_possible_true_vars_, possible_true);
|
||
solver()->SaveAndSetValue(&num_always_true_vars_, num_always_true_vars);
|
||
}
|
||
}
|
||
|
||
void UpdateVar() {
|
||
if (num_possible_true_vars_ == sum_var_->Min()) {
|
||
PushAllUnboundToOne();
|
||
} else if (num_always_true_vars_ == sum_var_->Max()) {
|
||
PushAllUnboundToZero();
|
||
}
|
||
}
|
||
|
||
void Update(int index) {
|
||
if (!inactive_) {
|
||
DCHECK(vars_[index]->Bound());
|
||
const int64 value = vars_[index]->Min(); // Faster than Value().
|
||
if (value == 0) {
|
||
solver()->SaveAndAdd(&num_possible_true_vars_, -1);
|
||
if (num_possible_true_vars_ == sum_var_->Min()) {
|
||
PushAllUnboundToOne();
|
||
}
|
||
} else {
|
||
DCHECK_EQ(1, value);
|
||
solver()->SaveAndAdd(&num_always_true_vars_, 1);
|
||
if (num_always_true_vars_ == sum_var_->Max()) {
|
||
PushAllUnboundToZero();
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
void PushAllUnboundToZero() {
|
||
int64 counter = 0;
|
||
solver()->SaveAndSetValue(&inactive_, 1);
|
||
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;
|
||
solver()->SaveAndSetValue(&inactive_, 1);
|
||
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 DebugStringInternal("SumBooleanEqualToVar");
|
||
}
|
||
|
||
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:
|
||
int num_possible_true_vars_;
|
||
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 Constraint {
|
||
public:
|
||
PositiveBooleanScalProdEqVar(Solver* const s,
|
||
const IntVar* const * vars,
|
||
int size,
|
||
const int64* const coefs,
|
||
IntVar* const var)
|
||
: Constraint(s),
|
||
size_(size),
|
||
vars_(new IntVar*[size_]),
|
||
coefs_(new int64[size_]),
|
||
var_(var),
|
||
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]);
|
||
}
|
||
|
||
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 (!var_->Bound()) {
|
||
Demon* const uv =
|
||
MakeConstraintDemon0(solver(),
|
||
this,
|
||
&PositiveBooleanScalProdEqVar::Propagate,
|
||
"Propagate");
|
||
var_->WhenRange(uv);
|
||
}
|
||
}
|
||
|
||
void Propagate() {
|
||
var_->SetRange(sum_of_bound_variables_.Value(),
|
||
sum_of_all_variables_.Value());
|
||
const int64 slack_up = var_->Max() - sum_of_bound_variables_.Value();
|
||
const int64 slack_down = sum_of_all_variables_.Value() - 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(),
|
||
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,
|
||
var_);
|
||
visitor->EndVisitConstraint(ModelVisitor::kScalProdEqual, this);
|
||
}
|
||
|
||
private:
|
||
int size_;
|
||
scoped_array<IntVar*> vars_;
|
||
scoped_array<int64> coefs_;
|
||
IntVar* const var_;
|
||
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);
|
||
AddDelegateName("Var", var);
|
||
if (size_ > 0) {
|
||
Constraint* const ct = s->RevAlloc(
|
||
new PositiveBooleanScalProdEqVar(s,
|
||
vars_.get(),
|
||
size_,
|
||
coefs_.get(),
|
||
var));
|
||
s->AddDelegateConstraint(ct);
|
||
}
|
||
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_;
|
||
};
|
||
|
||
// ----- API -----
|
||
|
||
} // namespace
|
||
Constraint* Solver::MakeSumLessOrEqual(const std::vector<IntVar*>& vars, int64 cst) {
|
||
return MakeSumLessOrEqual(vars.data(), vars.size(), cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeSumLessOrEqual(IntVar* const* vars,
|
||
int size,
|
||
int64 cst) {
|
||
if (cst == 1LL && AreAllBooleans(vars, size) && size > 2) {
|
||
return RevAlloc(new SumBooleanLessOrEqualToOne(this, vars, size));
|
||
} else {
|
||
return MakeLessOrEqual(MakeSum(vars, size), cst);
|
||
}
|
||
}
|
||
|
||
Constraint* Solver::MakeSumGreaterOrEqual(const std::vector<IntVar*>& vars,
|
||
int64 cst) {
|
||
return MakeSumGreaterOrEqual(vars.data(), vars.size(), cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeSumGreaterOrEqual(IntVar* const* vars,
|
||
int size,
|
||
int64 cst) {
|
||
if (cst == 1LL && AreAllBooleans(vars, size) && size > 2) {
|
||
return RevAlloc(new SumBooleanGreaterOrEqualToOne(this, vars, size));
|
||
} else {
|
||
return MakeGreaterOrEqual(MakeSum(vars, size), cst);
|
||
}
|
||
}
|
||
|
||
Constraint* Solver::MakeSumEquality(const std::vector<IntVar*>& vars, int64 cst) {
|
||
return MakeSumEquality(vars.data(), vars.size(), cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeSumEquality(IntVar* const* vars,
|
||
int size,
|
||
int64 cst) {
|
||
if (AreAllBooleans(vars, size) && size > 2) {
|
||
if (cst == 1) {
|
||
return RevAlloc(new SumBooleanEqualToOne(this, vars, size));
|
||
} else if (cst < 0 || cst > size) {
|
||
return MakeFalseConstraint();
|
||
} else {
|
||
return RevAlloc(new SumBooleanEqualToVar(this,
|
||
vars,
|
||
size,
|
||
MakeIntConst(cst)));
|
||
}
|
||
} else {
|
||
return RevAlloc(new SumConstraint(this, vars, size, MakeIntConst(cst)));
|
||
}
|
||
}
|
||
|
||
Constraint* Solver::MakeSumEquality(const std::vector<IntVar*>& vars,
|
||
IntVar* const var) {
|
||
return MakeSumEquality(vars.data(), vars.size(), var);
|
||
}
|
||
|
||
Constraint* Solver::MakeSumEquality(IntVar* const* vars,
|
||
int size,
|
||
IntVar* const var) {
|
||
if (AreAllBooleans(vars, size) && size > 2) {
|
||
return RevAlloc(new SumBooleanEqualToVar(this, vars, size, var));
|
||
} else {
|
||
return RevAlloc(new SumConstraint(this, vars, size, var));
|
||
}
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdEquality(const std::vector<IntVar*>& vars,
|
||
const std::vector<int64>& coefficients,
|
||
int64 cst) {
|
||
DCHECK_EQ(vars.size(), coefficients.size());
|
||
return MakeScalProdEquality(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 MakeScalProdEquality(vars.data(),
|
||
vars.size(),
|
||
coefficients.data(),
|
||
cst);
|
||
}
|
||
|
||
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)) {
|
||
// TODO(user) : bench BooleanScalProdEqVar with IntConst.
|
||
return solver->RevAlloc(new PositiveBooleanScalProdEqCst(solver,
|
||
vars,
|
||
size,
|
||
coefficients,
|
||
cst));
|
||
}
|
||
std::vector<IntVar*> terms;
|
||
for (int i = 0; i < size; ++i) {
|
||
terms.push_back(solver->MakeProd(vars[i], coefficients[i])->Var());
|
||
}
|
||
return solver->MakeEquality(solver->MakeSum(terms), cst);
|
||
}
|
||
} // namespace
|
||
|
||
Constraint* Solver::MakeScalProdEquality(IntVar* const * vars,
|
||
int size,
|
||
int64 const * coefficients,
|
||
int64 cst) {
|
||
return MakeScalProdEqualityFct<int64>(this, vars, size, coefficients, cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdEquality(IntVar* const * vars,
|
||
int size,
|
||
int const * coefficients,
|
||
int64 cst) {
|
||
return MakeScalProdEqualityFct<int>(this, vars, size, coefficients, cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdGreaterOrEqual(const std::vector<IntVar*>& vars,
|
||
const std::vector<int64>& coeffs,
|
||
int64 cst) {
|
||
DCHECK_EQ(vars.size(), coeffs.size());
|
||
return MakeScalProdGreaterOrEqual(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 MakeScalProdGreaterOrEqual(vars.data(),
|
||
vars.size(),
|
||
coeffs.data(),
|
||
cst);
|
||
}
|
||
|
||
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();
|
||
}
|
||
std::vector<IntVar*> terms;
|
||
for (int i = 0; i < size; ++i) {
|
||
terms.push_back(solver->MakeProd(vars[i], coefficients[i])->Var());
|
||
}
|
||
return solver->MakeGreaterOrEqual(solver->MakeSum(terms), cst);
|
||
}
|
||
} // namespace
|
||
|
||
Constraint* Solver::MakeScalProdGreaterOrEqual(IntVar* const * vars,
|
||
int size,
|
||
int64 const * coefficients,
|
||
int64 cst) {
|
||
return MakeScalProdGreaterOrEqualFct<int64>(this,
|
||
vars, size, coefficients, cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdGreaterOrEqual(IntVar* const * vars,
|
||
int size,
|
||
int const * coefficients,
|
||
int64 cst) {
|
||
return MakeScalProdGreaterOrEqualFct<int>(this,
|
||
vars, size, coefficients, cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdLessOrEqual(const std::vector<IntVar*>& vars,
|
||
const std::vector<int64>& coefficients,
|
||
int64 cst) {
|
||
DCHECK_EQ(vars.size(), coefficients.size());
|
||
return MakeScalProdLessOrEqual(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 MakeScalProdLessOrEqual(vars.data(),
|
||
vars.size(),
|
||
coefficients.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));
|
||
}
|
||
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(IntVar* const * vars,
|
||
int size,
|
||
int64 const * coefficients,
|
||
int64 cst) {
|
||
return MakeScalProdLessOrEqualFct<int64>(this, vars, size, coefficients, cst);
|
||
}
|
||
|
||
Constraint* Solver::MakeScalProdLessOrEqual(IntVar* const * vars,
|
||
int size,
|
||
int const * coefficients,
|
||
int64 cst) {
|
||
return MakeScalProdLessOrEqualFct<int>(this, vars, size, coefficients, cst);
|
||
}
|
||
|
||
IntExpr* Solver::MakeScalProd(const std::vector<IntVar*>& vars,
|
||
const std::vector<int64>& coefs) {
|
||
DCHECK_EQ(vars.size(), coefs.size());
|
||
return MakeScalProd(vars.data(), coefs.data(), vars.size());
|
||
}
|
||
|
||
IntExpr* Solver::MakeScalProd(const std::vector<IntVar*>& vars,
|
||
const std::vector<int>& coefs) {
|
||
DCHECK_EQ(vars.size(), coefs.size());
|
||
return MakeScalProd(vars.data(), coefs.data(), vars.size());
|
||
}
|
||
|
||
namespace {
|
||
template<class T> IntExpr* MakeScalProdFct(Solver* solver,
|
||
IntVar* const * vars,
|
||
const T* const coefs,
|
||
int size) {
|
||
if (size == 0 || AreAllNull<T>(coefs, size)) {
|
||
return solver->MakeIntConst(0LL);
|
||
}
|
||
if (AreAllBoundOrNull(vars, coefs, size)) {
|
||
int64 cst = 0;
|
||
for (int i = 0; i < size; ++i) {
|
||
cst += vars[i]->Min() * coefs[i];
|
||
}
|
||
return solver->MakeIntConst(cst);
|
||
}
|
||
if (AreAllBooleans(vars, size)) {
|
||
if (AreAllPositive<T>(coefs, size)) {
|
||
return solver->RevAlloc(
|
||
new PositiveBooleanScalProd(solver, vars, size, coefs));
|
||
} 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* negatives =
|
||
solver->RevAlloc(
|
||
new PositiveBooleanScalProd(solver,
|
||
negative_coef_vars.data(),
|
||
negative_coef_vars.size(),
|
||
negative_coefs.data()));
|
||
if (!positive_coefs.empty()) {
|
||
IntExpr* positives =
|
||
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(IntVar* const * vars,
|
||
const int64* const coefs,
|
||
int size) {
|
||
return MakeScalProdFct<int64>(this, vars, coefs, size);
|
||
}
|
||
|
||
IntExpr* Solver::MakeScalProd(IntVar* const * vars,
|
||
const int* const coefs,
|
||
int size) {
|
||
return MakeScalProdFct<int>(this, vars, coefs, size);
|
||
}
|
||
|
||
|
||
} // namespace operations_research
|