71 lines
2.2 KiB
C++
71 lines
2.2 KiB
C++
// Copyright 2010-2025 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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// Finds a rectangle with maximum available area for given perimeter
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// using AddMultiplicationEquality
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// [START program]
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#include <stdlib.h>
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#include "absl/base/log_severity.h"
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#include "absl/log/globals.h"
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#include "ortools/base/init_google.h"
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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_solver.h"
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namespace operations_research {
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namespace sat {
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void NonLinearSatProgram() {
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CpModelBuilder cp_model;
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const int perimeter = 20;
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const Domain sides_domain(0, perimeter);
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const IntVar x = cp_model.NewIntVar(sides_domain);
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const IntVar y = cp_model.NewIntVar(sides_domain);
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cp_model.AddEquality(2 * (x + y), perimeter);
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const Domain area_domain(0, perimeter * perimeter);
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const IntVar area = cp_model.NewIntVar(area_domain);
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cp_model.AddMultiplicationEquality(area, x, y);
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cp_model.Maximize(area);
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const CpSolverResponse response = Solve(cp_model.Build());
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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) << "x = " << SolutionIntegerValue(response, x);
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LOG(INFO) << "y = " << SolutionIntegerValue(response, y);
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LOG(INFO) << "s = " << SolutionIntegerValue(response, area);
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} else {
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LOG(INFO) << "No solution found.";
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}
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}
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} // namespace sat
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} // namespace operations_research
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int main(int argc, char* argv[]) {
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InitGoogle(argv[0], &argc, &argv, true);
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absl::SetStderrThreshold(absl::LogSeverityAtLeast::kInfo);
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operations_research::sat::NonLinearSatProgram();
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return EXIT_SUCCESS;
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}
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// [END program]
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