49 lines
1.7 KiB
Java
49 lines
1.7 KiB
Java
// Copyright 2010-2022 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.
|
|
|
|
package com.google.ortools.sat.samples;
|
|
|
|
import com.google.ortools.Loader;
|
|
import com.google.ortools.sat.CpModel;
|
|
import com.google.ortools.sat.CpSolver;
|
|
import com.google.ortools.sat.CpSolverStatus;
|
|
import com.google.ortools.sat.IntVar;
|
|
import com.google.ortools.sat.LinearExpr;
|
|
|
|
/**
|
|
* In a field of rabbits and pheasants, there are 20 heads and 56 legs. How many rabbits and
|
|
* pheasants are there?
|
|
*/
|
|
public class RabbitsAndPheasantsSat {
|
|
public static void main(String[] args) throws Exception {
|
|
Loader.loadNativeLibraries();
|
|
// Creates the model.
|
|
CpModel model = new CpModel();
|
|
// Creates the variables.
|
|
IntVar r = model.newIntVar(0, 100, "r");
|
|
IntVar p = model.newIntVar(0, 100, "p");
|
|
// 20 heads.
|
|
model.addEquality(LinearExpr.newBuilder().add(r).add(p), 20);
|
|
// 56 legs.
|
|
model.addEquality(LinearExpr.newBuilder().addTerm(r, 4).addTerm(p, 2), 56);
|
|
|
|
// Creates a solver and solves the model.
|
|
CpSolver solver = new CpSolver();
|
|
CpSolverStatus status = solver.solve(model);
|
|
|
|
if (status == CpSolverStatus.OPTIMAL) {
|
|
System.out.println(solver.value(r) + " rabbits, and " + solver.value(p) + " pheasants");
|
|
}
|
|
}
|
|
}
|