Move java examples

examples/java/ToNum.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 ToNum {
+
+  static {
+    System.loadLibrary("jniortools");
+  }
+
+
+  /**
+   *
+   *  toNum(solver, a, num, base)
+   *
+   *  channelling between the array a and the number num
+   *
+   */
+  private static void toNum(Solver solver, IntVar[] a, IntVar num, int base) {
+    int len = a.length;
+
+    IntVar[] tmp = new IntVar[len];
+    for(int i = 0; i < len; i++) {
+      tmp[i] = solver.makeProd(a[i], (int)Math.pow(base,(len-i-1))).var();
+    }
+    solver.addConstraint(
+        solver.makeEquality(solver.makeSum(tmp).var(), num));
+  }
+
+
+  /**
+   *
+   * Implements toNum: channeling between a number and an array.
+   * See http://www.hakank.org/google_or_tools/toNum.py
+   *
+   */
+  private static void solve() {
+
+    Solver solver = new Solver("ToNum");
+
+    int n = 5;
+    int base = 10;
+
+
+    //
+    // variables
+    //
+    IntVar[] x =  solver.makeIntVarArray(n, 0, base - 1, "x");
+    IntVar num = solver.makeIntVar(0, (int)Math.pow(base, n) - 1 , "num");
+
+
+
+    //
+    // constraints
+    //
+    solver.addConstraint(solver.makeAllDifferent(x));
+
+
+    toNum(solver, x, num, base);
+
+    // extra constraint (just for fun):
+    // second digit should be 7
+    // solver.addConstraint(solver.makeEquality(x[1], 7));
+
+
+    //
+    // search
+    //
+    DecisionBuilder db = solver.makePhase(x,
+                                          solver.CHOOSE_FIRST_UNBOUND,
+                                          solver.ASSIGN_MIN_VALUE);
+
+    solver.newSearch(db);
+
+    //
+    // output
+    //
+    while (solver.nextSolution()) {
+      System.out.print("num: " + num.value() + ": ");
+      for(int i = 0; i < n; i++) {
+        System.out.print(x[i].value() + " ");
+      }
+      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 {
+    ToNum.solve();
+  }
+}