Changeset 15511 for branches/GeneralizedQAP/HeuristicLab.Problems.GeneralizedQuadraticAssignment/3.3/Moves/StochasticNMoveSingleMoveGenerator.cs

Timestamp:

12/11/17 23:06:32 (7 years ago)

Author:

abeham

Message:

#1614: Improved performance by switching from Dictionary to Array

File:

• branches/GeneralizedQAP/HeuristicLab.Problems.GeneralizedQuadraticAssignment/3.3/Moves/StochasticNMoveSingleMoveGenerator.cs (modified) (3 diffs)

branches/GeneralizedQAP/HeuristicLab.Problems.GeneralizedQuadraticAssignment/3.3/Moves/StochasticNMoveSingleMoveGenerator.cs

@@ -20 +20 @@
 #endregion
 
+using System;
 using System.Collections.Generic;
+using System.Linq;
 using HeuristicLab.Common;
 using HeuristicLab.Core;
@@ -28 +30 @@
 using HeuristicLab.Parameters;
 using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
+using HeuristicLab.Random;
 
 namespace HeuristicLab.Problems.GeneralizedQuadraticAssignment {
@@ -55 +58 @@
 
     public static NMove GenerateExactlyN(IRandom random, IntegerVector assignment, int n, DoubleArray capacities) {
-      int[] equipments = new int[n], locations = new int[n];
-      HashSet<int> chosenEquipments = new HashSet<int>();
-      for (int i = 0; i < n; i++) {
+      if (capacities.Length <= 1) throw new ArgumentException("There must be at least two locations.");
+      var dim = assignment.Length;
+      var reassignment = new int[dim];
+      var equipments = Enumerable.Range(0, dim).SampleRandomWithoutRepetition(random, n, dim).ToList();
+      for (var i = 0; i < n; i++) {
+        var equip = equipments[i];
         do {
-          equipments[i] = random.Next(assignment.Length);
-        } while (chosenEquipments.Contains(equipments[i]));
-        chosenEquipments.Add(equipments[i]);
-        do {
-          locations[i] = random.Next(capacities.Length);
-        } while (locations[i] == assignment[equipments[i]]);
+          reassignment[equip] = random.Next(capacities.Length) + 1;
+        } while (reassignment[equip] == assignment[equip] + 1);
       }
-      return new NMove(equipments, locations);
+      return new NMove(reassignment, equipments);
     }