mutateknowledge.java

用于求解TSP(Traveling salesman problem

/**
 * Description: The description of basic knolwedge for mutating edges.
 *
 * @ Author        Create/Modi     Note
 * Xiaofeng Xie    Apr 12, 2005     For TSP problem
 * Xiaofeng Xie    Apr 28, 2006    MAOS-TSP Beta 1.1.002
 *
 * @version 1.0
 * @Since SWAF1.0
 */

package implement.TSP.knowledge;

import Global.methods.*;

import implement.TSP.represent.*;

public class MutateKnowledge {
  public static int get2EdgeChangeDiffValue(IGetLocalCostEngine distEngine, int[] tour, int node1AID, int node2AID) {
    int n = tour.length;
    return get2EdgeChangeDiffValue(distEngine,
      tour[node1AID],
      tour[BasicArray.getSuccessorID(n, node1AID)],
      tour[node2AID],
      tour[BasicArray.getSuccessorID(n, node2AID)]);
  }

  // From Edge(node1A, node1B)+Edge(node2A, node2B)
  //   -> Edge(node1A, node2A)+Edge(node1B, node2B)
  public static int get2EdgeChangeDiffValue(IGetLocalCostEngine distEngine, int node1A, int node1B, int node2A, int node2B) {
    return  distEngine.getLocalCost(node1A, node2A)
          + distEngine.getLocalCost(node1B, node2B)
          - distEngine.getLocalCost(node1A, node1B)
          - distEngine.getLocalCost(node2A, node2B);
  }

  // From Edge(node1A, node1B)+Edge(node2A, node2B)
  //   -> Edge(node1A, node2A)+Edge(node1B, node2B)
  //  while neglecting Edge(node1A, node1B)
  public static int getPartial2EdgeChangeDiffValue(IGetLocalCostEngine distEngine, int node1A, int node1B, int node2A, int node2B) {
    return  distEngine.getLocalCost(node1B, node2B)
          - distEngine.getLocalCost(node1A, node1B)
          - distEngine.getLocalCost(node2A, node2B);
  }
}