本文借鉴http://www.cnblogs.com/liuzhen1995/p/6535025.html 算法原理，想要理解SPFA的原理的话可以先去了解一下，这里提供的是一种基于邻接矩阵的SPFA实现代码，利用java语言。
package Dijkstra_有权_spfa;
/*
*这个邻接矩阵 spfa
*/
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
public class My_spfa_邻接矩阵 {
private static final int INF = Integer.MAX_VALUE;
private int [][] weight;
private int nodes;
private boolean []flag ;
public My_spfa_邻接矩阵(int [][] weight,int nodes)
{
this.weight=weight;
this.nodes = nodes;
}
public void getSpfa(int src,int [] dist,int [] path)
{
flag=new boolean [nodes];
for(int i = 0;i <nodes;i++)
{
dist[i]=INF;
}
Queue<Integer> queue = new LinkedList<Integer>();
queue.add(src);
flag[src]= true;
dist[src]= 0;
while(!queue.isEmpty())
{
int out = queue.poll();
for(int i = 0;i<nodes;i++) // 对于第一个出队点的找所有相邻点
{
if(weight[out][i]!=INF&&dist[i]>dist[out]+weight[out][i]) // 判断一波邻接点，哇，好厉害啊
{
dist[i]=dist[out]+weight[out][i];
if(!flag[i])
{
queue.add(i);
flag[i]=true;
path[out]=i;
}
}
}
flag[out]=false; //找出所有相邻点并更新最短距离后重置标志。
}
for(int i = 0;i<nodes;i++)
{
System.out.print("点"+i+"距离为"+dist[i] +"\n");
// System.out.print(path[i]);
}
}
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int nodes = scan.nextInt();
int edges = scan.nextInt();
int [][]weight = new int[nodes][nodes];
for (int i = 0; i < nodes; i++)
for (int j = 0; j < nodes; j++)
{
if(i==j)
weight[i][j]=0;
else
weight[i][j] = INF;
}
int src, des, content;
for (int i = 0; i < edges; i++)
{
src = scan.nextInt();
des = scan.nextInt();
content = scan.nextInt();
weight[src][des] = content;
// weight[des][src] = content;
}
int[] path = new int[nodes];
int[] dist = new int[nodes];
My_spfa_邻接矩阵 M = new My_spfa_邻接矩阵(weight, nodes);
M.getSpfa(0,dist,path);
}
}