算法复习 - Dijkstra算法（迪杰斯特拉算法）

• Dijkstra.java

package map;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
* Created by pokerface_lx on 16/6/20.
* 使用迪杰斯特拉算法计算某节点到图中所有节点的最短距离
*/
public class Dijkstra {

   private static List openList;
   private static List closeList;
   private static int[] results;
   private static int choose;

   public static void solve(int[][] map) {
       openList = new ArrayList<>();
       closeList = new ArrayList<>();
       for (int i = 0; i < map.length; i++) {
           openList.add(i);
       }
       results = new int[map.length];
       for (int i = 0; i < results.length; i++) {
           results[i] = -1;
       }
       int startIndex = map.length - 1;
       openList.remove(startIndex);
       closeList.add(startIndex);
       results[startIndex] = 0;
       System.out.println("CLOSE RESULTS CHOOSE");
       showStatus();
       while (openList.size() > 0) {
           int lastChoose = closeList.get(closeList.size() - 1);
           for (int i = 0; i < map.length; i++) {
               if (results[i] == -1 && map[lastChoose][i] != -1) {
                   results[i] = map[lastChoose][i] + results[lastChoose];
               }
               if (results[i] != -1 && map[lastChoose][i] != -1 &&
                       (map[lastChoose][i] + results[lastChoose] < results[i])) {
                   results[i] = map[lastChoose][i] + results[lastChoose];
               }
           }
           choose = -1;
           int minDis = Integer.MAX_VALUE;
           for (int i : openList) {
               if (results[i] != -1 && results[i] != 0 && results[i] < minDis) {
                   minDis = results[i];
                   choose = i;
               }
           }
           openList.remove(new Integer(choose));
           closeList.add(choose);
           showStatus();
       }
   }

   private static void showStatus() {
       System.out.println(closeList.toString() + " " + Arrays.toString(results) + " " + choose);
   }

   public static void main(String[] args) {
       Dijkstra.solve(MapFactory.getMapForDijkstra());
   }

}