Knapsack.java

// Copyright 2010-2018 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.

import com.google.ortools.algorithms.KnapsackSolver;

/** Sample showing how to model using the knapsack solver. */
public class Knapsack {
  static {
    System.loadLibrary("jniortools");
  }

  private static void solve() {
    KnapsackSolver solver =
        new KnapsackSolver(
            KnapsackSolver.SolverType.KNAPSACK_MULTIDIMENSION_BRANCH_AND_BOUND_SOLVER, "test");
    final long[] profits = {
      360, 83, 59, 130, 431, 67, 230, 52, 93,
      125, 670, 892, 600, 38, 48, 147, 78, 256,
      63, 17, 120, 164, 432, 35, 92, 110, 22,
      42, 50, 323, 514, 28, 87, 73, 78, 15,
      26, 78, 210, 36, 85, 189, 274, 43, 33,
      10, 19, 389, 276, 312
    };

    final long[][] weights = {
      {
        7, 0, 30, 22, 80, 94, 11, 81, 70,
        64, 59, 18, 0, 36, 3, 8, 15, 42,
        9, 0, 42, 47, 52, 32, 26, 48, 55,
        6, 29, 84, 2, 4, 18, 56, 7, 29,
        93, 44, 71, 3, 86, 66, 31, 65, 0,
        79, 20, 65, 52, 13
      }
    };

    final long[] capacities = {850};

    final long optimalProfit = 7534;
    System.out.println("Solving knapsack with " + profits.length + " items");

    solver.init(profits, weights, capacities);

    final long computedProfit = solver.solve();

    System.out.println("Optimal_Profit = " + computedProfit + "/" + optimalProfit);
  }

  public static void main(String[] args) throws Exception {
    Knapsack.solve();
  }
}