Move java examples

examples/java/Seseman.java

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+// 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 Seseman {
+
+  static {
+    System.loadLibrary("jniortools");
+  }
+
+
+  /**
+   *
+   * Solves the Seseman convent problem.
+   * See http://www.hakank.org/google_or_tools/seseman.py
+   *
+   */
+  private static void solve(int n) {
+
+    Solver solver = new Solver("Seseman");
+
+    //
+    // data
+    //
+    final int border_sum = n * n;
+
+    //
+    // 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(0, n * n);
+        x_flat[i * n + j] = x[i][j];
+      }
+    }
+
+    IntVar total_sum = solver.makeSum(x_flat).var();
+
+
+    //
+    // constraints
+    //
+
+    // zero in all middle cells
+    for(int i = 1; i < n-1; i++) {
+      for(int j = 1; j < n-1; j++) {
+        solver.addConstraint(solver.makeEquality(x[i][j], 0));
+      }
+    }
+
+    // all borders must be >= 1
+    for(int i = 0; i < n; i++) {
+      for(int j = 0; j < n; j++) {
+        if (i == 0 || j == 0 || i == n - 1 || j == n - 1) {
+          solver.addConstraint(solver.makeGreaterOrEqual(x[i][j], 1));
+        }
+      }
+    }
+
+    // sum the four borders
+    IntVar[] border1 = new IntVar[n];
+    IntVar[] border2 = new IntVar[n];
+    IntVar[] border3 = new IntVar[n];
+    IntVar[] border4 = new IntVar[n];
+    for(int i = 0; i < n; i++) {
+      border1[i] = x[i][0];
+      border2[i] = x[i][n - 1];
+      border3[i] = x[0][i];
+      border4[i] = x[n - 1][i];
+    }
+    solver.addConstraint(
+        solver.makeSumEquality(border1, border_sum));
+
+    solver.addConstraint(
+        solver.makeSumEquality(border2, border_sum));
+
+    solver.addConstraint(
+        solver.makeSumEquality(border3, border_sum));
+
+    solver.addConstraint(
+        solver.makeSumEquality(border4, border_sum));
+
+
+    //
+    // search
+    //
+
+    DecisionBuilder db = solver.makePhase(x_flat,
+                                          solver.INT_VAR_DEFAULT,
+                                          solver.INT_VALUE_DEFAULT);
+    solver.newSearch(db);
+
+    while (solver.nextSolution()) {
+      System.out.println("total_sum: " + total_sum.value());
+      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 {
+    int n = 3;
+    if (args.length > 0) {
+      n = Integer.parseInt(args[0]);
+    }
+    Seseman.solve(n);
+  }
+}