Move java examples

2018-07-06 21:03:33 +02:00
parent 6485017458
commit 13a566bed4
58 changed files with 340 additions and 693 deletions
--- a/examples/java/NQueens2.java
+++ b/examples/java/NQueens2.java
@@ -0,0 +1,110 @@
+// 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 NQueens2 {
+
+  static {
+    System.loadLibrary("jniortools");
+  }
+
+
+  /**
+   *
+   * Solves the N Queens problem.
+   * See http://www.hakank.org/google_or_tools/nqueens2.py
+   *
+   */
+  private static void solve(int n, int num, int print) {
+
+    Solver solver = new Solver("NQueens");
+
+    System.out.println("n: " + n);
+
+    //
+    // variables
+    //
+    IntVar[] q = solver.makeIntVarArray(n, 0, n-1, "q");
+
+    //
+    // constraints
+    //
+    solver.addConstraint(solver.makeAllDifferent(q));
+
+    IntVar[] q1 = new IntVar[n];
+    IntVar[] q2 = new IntVar[n];
+    for(int i = 0; i < n; i++) {
+      q1[i] = solver.makeSum(q[i], i).var();
+      q2[i] = solver.makeSum(q[i], -i).var();
+    }
+    solver.addConstraint(solver.makeAllDifferent(q1));
+    solver.addConstraint(solver.makeAllDifferent(q2));
+
+    //
+    // Solve
+    //
+    DecisionBuilder db = solver.makePhase(q,
+                                          solver.CHOOSE_MIN_SIZE_LOWEST_MAX,
+                                          solver.ASSIGN_CENTER_VALUE);
+    solver.newSearch(db);
+    int c = 0;
+    while (solver.nextSolution()) {
+      if (print != 0) {
+        for(int i = 0; i < n; i++) {
+          System.out.print(q[i].value() + " ");
+        }
+        System.out.println();
+      }
+      c++;
+      if (num > 0 && c >= num) {
+        break;
+      }
+    }
+    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 = 8;
+    int num = 0;
+    int print = 1;
+
+    if (args.length > 0) {
+      n = Integer.parseInt(args[0]);
+    }
+
+    if (args.length > 1) {
+      num = Integer.parseInt(args[1]);
+    }
+
+    if (args.length > 2) {
+      print = Integer.parseInt(args[2]);
+    }
+
+
+    NQueens2.solve(n, num, print);
+  }
+}