package com.blyang; 
 
public class Floyd { 
   
  int[][] Matrix; 
  char[] Nodes; 
   
  private final int INF = Integer.MAX_VALUE; 
   
  public Floyd(char[] Nodes, int[][] Matrix){ 
    this.Nodes = Nodes; 
    this.Matrix = Matrix; 
  } 
   
  public void floyd(){ 
     
    int[][] distance = new int[Nodes.length][Nodes.length]; 
     
    // 初始化距離矩陣 
    for(int i=0; i<Nodes.length; i++){ 
      for(int j=0; j<Nodes.length; j++){ 
        distance[i][j] = Matrix[i][j]; 
      } 
    } 
     
    //循環(huán)更新矩陣的值 
    for(int k=0; k<Nodes.length; k++){ 
      for(int i=0; i<Nodes.length; i++){ 
        for(int j=0; j<Nodes.length; j++){ 
          int temp = (distance[i][k] == INF || distance[k][j] == INF) ? INF : distance[i][k] + distance[k][j]; 
          if(distance[i][j] > temp){ 
            distance[i][j] = temp; 
          } 
        } 
      } 
    } 
     
    // 打印floyd最短路徑的結果 
    System.out.printf("floyd: \n"); 
    for (int i = 0; i < Nodes.length; i++) { 
      for (int j = 0; j < Nodes.length; j++) 
        System.out.printf("%12d ", distance[i][j]); 
      System.out.printf("\n"); 
    } 
  } 
} 

package com.blyang; 
 
public class Main { 
 
 
   
  public static void main(String[] args) { 
    int INF = Integer.MAX_VALUE; 
     
    char[] Nodes = {'0', '1', '2', '3'}; 
    int matrix[][] = { 
         /*A*//*B*//*C*//*D*/ 
     /*A*/ {  0,  1,  2,  1}, 
     /*B*/ { INF,  0, INF, INF}, 
     /*C*/ { INF,  3,  0,  1}, 
     /*D*/ { INF,  1,  1,  0}, 
     }; 
       
    int[] dist = new int[Nodes.length]; 
   
    Floyd floyd = new Floyd(Nodes, matrix); 
    floyd.floyd(); 
 
  } 
   
}