SPFA模板

 

void SPFA(int s) 
{
    for(int i=1;i<=n;i++)
 {
        d[i] = MAX;
    }
 int queue[N*N] = {0};
 bool visit[N] = {false};
    int front = 0, rear = 1;
 //int path[N];
    queue[front] = s;
 visit[s] = true; 
 d[s] = 0;
    while(front<rear)
 {   
        int u = queue[front];
        visit[u] = false;
        for(int i=1; i<=n; i++)
  {
            if (d[i]>d[u]+ edges[u][i])
   {
                d[i]= d[u]+edges[u][i];
                //path[i] = u;
                if( !visit[i] )
    {
                    visit[i] = true;
                    queue[rear++] = i;
                }
            }
  }
  front++;
    }
}
/*调用时，初始结点s，目标结点e，则
SPFA(s);
cout<<d[e]<<endl;
即可。注意结点是从1存储到N。
不能连通时值为MAX。
*/