求無向圖中指定點到點以前最短路徑

求無向圖中任意兩點之間最短距離

在本例中，假設求1->2之間的最短距離，很容易獲得f(2) = min{f(3)+1,f(5)+1}
f(d) = min(f(0)>0->f(0)+1...f(d-1)>0->f(d-1)+1)

JAVA編碼實現

public static void main(String[] args) {
    int[][] maps = {
            {0, 0, 0, 0, 0, 0},
            {0, 0, 0, 1, 1, 0},
            {0, 0, 0, 1, 0, 1},
            {0, 1, 1, 0, 0, 1},
            {0, 1, 0, 0, 0, 1},
            {0, 0, 1, 1, 1, 0}
    };


    int shortDistance = shortDistance(maps, 1, 2);
    System.out.println("最短路徑:" + shortDistance);
  }

  public static int shortDistance(int[][] maps, int x, int y) {
    int min = maps[x][y];
    if (min == 0) {
      for (int i = 1; i < maps[y].length; i++) {
        if (maps[x][i] == 1) {
          int tmp = shortDistance(maps, x, i);
          if (tmp + 1 < min || min == 0) {
            min = tmp + 1;
          }
        }
      }
    }
    return min;
  }