rabbits_and_pheasants_sat.cc

// Copyright 2010-2021 Google LLC
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "ortools/sat/cp_model.h"

namespace operations_research {
namespace sat {

void RabbitsAndPheasantsSat() {
  CpModelBuilder cp_model;

  const Domain all_animals(0, 20);
  const IntVar rabbits = cp_model.NewIntVar(all_animals).WithName("rabbits");
  const IntVar pheasants =
      cp_model.NewIntVar(all_animals).WithName("pheasants");

  cp_model.AddEquality(LinearExpr::Sum({rabbits, pheasants}), 20);
  cp_model.AddEquality(LinearExpr::ScalProd({rabbits, pheasants}, {4, 2}), 56);

  const CpSolverResponse response = Solve(cp_model.Build());

  if (response.status() == CpSolverStatus::OPTIMAL) {
    // Get the value of x in the solution.
    LOG(INFO) << SolutionIntegerValue(response, rabbits) << " rabbits, and "
              << SolutionIntegerValue(response, pheasants) << " pheasants";
  }
}

}  // namespace sat
}  // namespace operations_research

int main() {
  operations_research::sat::RabbitsAndPheasantsSat();

  return EXIT_SUCCESS;
}