// Copyright 2011 Hakan Kjellerstrand hakank@gmail.com // 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 java.io.*; import java.util.*; import java.text.*; import com.google.ortools.constraintsolver.DecisionBuilder; import com.google.ortools.constraintsolver.IntVar; import com.google.ortools.constraintsolver.Solver; public class Strimko2 { static { System.loadLibrary("jniortools"); } /** * * Solves a Strimko problem. * See http://www.hakank.org/google_or_tools/strimko2.py * */ private static void solve() { Solver solver = new Solver("Strimko2"); // // data // int[][] streams = {{1,1,2,2,2,2,2}, {1,1,2,3,3,3,2}, {1,4,1,3,3,5,5}, {4,4,3,1,3,5,5}, {4,6,6,6,7,7,5}, {6,4,6,4,5,5,7}, {6,6,4,7,7,7,7}}; // Note: This is 1-based int[][] placed = {{2,1,1}, {2,3,7}, {2,5,6}, {2,7,4}, {3,2,7}, {3,6,1}, {4,1,4}, {4,7,5}, {5,2,2}, {5,6,6}}; int n = streams.length; int num_placed = placed.length; // // variables // IntVar[][] x = new IntVar[n][n]; IntVar[] x_flat = new IntVar[n * n]; for(int i = 0; i < n; i++) { for(int j = 0; j < n; j++) { x[i][j] = solver.makeIntVar(1, n, "x[" + i + "," + j + "]"); x_flat[i * n + j] = x[i][j]; } } // // constraints // // all rows and columns must be unique, i.e. a Latin Square for(int i = 0; i < n; i++) { IntVar[] row = new IntVar[n]; IntVar[] col = new IntVar[n]; for(int j = 0; j < n; j++) { row[j] = x[i][j]; col[j] = x[j][i]; } solver.addConstraint(solver.makeAllDifferent(row)); solver.addConstraint(solver.makeAllDifferent(col)); } // streams for(int s = 1; s <= n; s++) { ArrayList tmp = new ArrayList(); for(int i = 0; i < n; i++) { for(int j = 0; j < n; j++) { if (streams[i][j] == s) { tmp.add(x[i][j]); } } } solver.addConstraint( solver.makeAllDifferent(tmp.toArray(new IntVar[1]))); } // placed for(int i = 0; i < num_placed; i++) { // note: also adjust to 0-based solver.addConstraint( solver.makeEquality(x[placed[i][0] - 1][placed[i][1] - 1], placed[i][2])); } // // search // DecisionBuilder db = solver.makePhase(x_flat, solver.INT_VAR_DEFAULT, solver.INT_VALUE_DEFAULT); solver.newSearch(db); // // output // while (solver.nextSolution()) { for(int i = 0; i < n; i++) { for(int j = 0; j < n; j++) { System.out.print(x[i][j].value() + " "); } System.out.println(); } System.out.println(); } solver.endSearch(); // Statistics System.out.println(); System.out.println("Solutions: " + solver.solutions()); System.out.println("Failures: " + solver.failures()); System.out.println("Branches: " + solver.branches()); System.out.println("Wall time: " + solver.wallTime() + "ms"); } public static void main(String[] args) throws Exception { Strimko2.solve(); } }