88 lines
2.6 KiB
C++
88 lines
2.6 KiB
C++
// Copyright 2010-2021 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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// [START program]
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// [START import]
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#include <stdint.h>
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#include <stdlib.h>
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#include <algorithm>
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#include "ortools/base/logging.h"
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#include "ortools/sat/cp_model.h"
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#include "ortools/sat/cp_model.pb.h"
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#include "ortools/sat/cp_model_solver.h"
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#include "ortools/util/sorted_interval_list.h"
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// [END import]
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namespace operations_research {
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namespace sat {
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void CpSatExample() {
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// [START model]
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CpModelBuilder cp_model;
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// [END model]
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// [START variables]
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int64_t var_upper_bound = std::max({50, 45, 37});
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const Domain domain(0, var_upper_bound);
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const IntVar x = cp_model.NewIntVar(domain).WithName("x");
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const IntVar y = cp_model.NewIntVar(domain).WithName("y");
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const IntVar z = cp_model.NewIntVar(domain).WithName("z");
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// [END variables]
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// [START constraints]
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cp_model.AddLessOrEqual(2 * x + 7 * y + 3 * z, 50);
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cp_model.AddLessOrEqual(3 * x - 5 * y + 7 * z, 45);
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cp_model.AddLessOrEqual(5 * x + 2 * y - 6 * z, 37);
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// [END constraints]
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// [START objective]
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cp_model.Maximize(2 * x + 2 * y + 3 * z);
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// [END objective]
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// Solving part.
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// [START solve]
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const CpSolverResponse response = Solve(cp_model.Build());
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// [END solve]
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// [START print_solution]
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if (response.status() == CpSolverStatus::OPTIMAL ||
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response.status() == CpSolverStatus::FEASIBLE) {
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// Get the value of x in the solution.
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LOG(INFO) << "Maximum of objective function: "
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<< response.objective_value();
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LOG(INFO) << "x = " << SolutionIntegerValue(response, x);
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LOG(INFO) << "y = " << SolutionIntegerValue(response, y);
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LOG(INFO) << "z = " << SolutionIntegerValue(response, z);
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} else {
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LOG(INFO) << "No solution found.";
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}
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// [END print_solution]
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// Statistics.
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// [START statistics]
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LOG(INFO) << "Statistics";
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LOG(INFO) << CpSolverResponseStats(response);
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// [END statistics]
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}
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} // namespace sat
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} // namespace operations_research
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int main() {
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operations_research::sat::CpSatExample();
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return EXIT_SUCCESS;
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}
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// [END program]
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