62 lines
2.2 KiB
C++
62 lines
2.2 KiB
C++
// Copyright 2010-2022 Google LLC
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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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// Constraint programming example that shows how to use the API.
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#include "ortools/base/logging.h"
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#include "ortools/constraint_solver/constraint_solver.h"
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namespace operations_research {
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void RunConstraintProgrammingExample() {
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// Instantiate the solver.
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Solver solver("ConstraintProgrammingExample");
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const int64_t numVals = 3;
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// Define decision variables.
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IntVar* const x = solver.MakeIntVar(0, numVals - 1, "x");
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IntVar* const y = solver.MakeIntVar(0, numVals - 1, "y");
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IntVar* const z = solver.MakeIntVar(0, numVals - 1, "z");
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// Define constraints.
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std::vector<IntVar*> xyvars = {x, y};
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solver.AddConstraint(solver.MakeAllDifferent(xyvars));
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LOG(INFO) << "Number of constraints: " << solver.constraints();
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// Create decision builder to search for solutions.
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std::vector<IntVar*> allvars = {x, y, z};
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DecisionBuilder* const db = solver.MakePhase(
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allvars, Solver::CHOOSE_FIRST_UNBOUND, Solver::ASSIGN_MIN_VALUE);
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solver.NewSearch(db);
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while (solver.NextSolution()) {
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LOG(INFO) << "Solution"
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<< ": x = " << x->Value() << "; y = " << y->Value()
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<< "; z = " << z->Value();
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}
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solver.EndSearch();
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LOG(INFO) << "Number of solutions: " << solver.solutions();
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LOG(INFO) << "";
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LOG(INFO) << "Advanced usage:";
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LOG(INFO) << "Problem solved in " << solver.wall_time() << "ms";
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LOG(INFO) << "Memory usage: " << Solver::MemoryUsage() << " bytes";
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}
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} // namespace operations_research
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int main(int argc, char** argv) {
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google::InitGoogleLogging(argv[0]);
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absl::SetFlag(&FLAGS_logtostderr, 1);
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operations_research::RunConstraintProgrammingExample();
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return EXIT_SUCCESS;
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}
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