Changeset 5931 for branches/QAP/HeuristicLab.Encodings.PermutationEncoding/3.3/Moves/Swap2

Timestamp:

04/02/11 16:45:04 (14 years ago)

Author:

abeham

Message:

#1330

• changes according to the review

Location:

branches/QAP/HeuristicLab.Encodings.PermutationEncoding/3.3/Moves/Swap2

Files:

• ExhaustiveSwap2MoveGenerator.cs (modified) (1 diff)
• StochasticSwap2SingleMoveGenerator.cs (modified) (1 diff)

branches/QAP/HeuristicLab.Encodings.PermutationEncoding/3.3/Moves/Swap2/ExhaustiveSwap2MoveGenerator.cs

@@ -43 +43 @@
       if (length == 1) throw new ArgumentException("ExhaustiveSwap2MoveGenerator: There cannot be an Swap move given a permutation of length 1.", "permutation");
       int totalMoves = (length) * (length - 1) / 2;
-      Swap2Move[] moves = null;
+      Swap2Move[] moves = new Swap2Move[totalMoves];
       int count = 0;
 
-      if (permutation.PermutationType == PermutationTypes.RelativeUndirected) {
-        if (totalMoves - 3 > 0) {
-          moves = new Swap2Move[totalMoves - 3];
-          for (int i = 0; i < length - 1; i++) {
-            for (int j = i + 1; j < length; j++) {
-              if (j - i >= length - 2) continue;
-              moves[count++] = new Swap2Move(i, j);
-            }
-          }
-        } else { // when length is 3 or less, there's actually no difference, but for the sake of not crashing the algorithm create a dummy move
-          moves = new Swap2Move[1];
-          moves[0] = new Swap2Move(0, 1);
+      for (int i = 0; i < length - 1; i++)
+        for (int j = i + 1; j < length; j++) {
+          moves[count++] = new Swap2Move(i, j);
         }
-      } else {
-        moves = new Swap2Move[totalMoves];
-        for (int i = 0; i < length - 1; i++)
-          for (int j = i + 1; j < length; j++) {
-            moves[count++] = new Swap2Move(i, j);
-          }
-      }
       return moves;
     }

branches/QAP/HeuristicLab.Encodings.PermutationEncoding/3.3/Moves/Swap2/StochasticSwap2SingleMoveGenerator.cs

@@ -49 +49 @@
     public static Swap2Move Apply(Permutation permutation, IRandom random) {
       int length = permutation.Length;
-      if (length == 1) throw new ArgumentException("StochasticSwap2SingleMoveGenerator: There cannot be an Swap move given a permutation of length 1.", "permutation");
-      int index1 = random.Next(length - 1);
-      int index2 = random.Next(index1 + 1, length);
+      if (length < 2) throw new ArgumentException("StochasticSwap2SingleMoveGenerator: There cannot be a swap-2 move given a permutation of length less than 2.", "permutation");
+      int index1 = random.Next(length), index2 = 0;
+      do {
+        index2 = random.Next(length);
+      } while (index1 == index2);
       return new Swap2Move(index1, index2);
     }