最短路~spfa模板

#include<iostream>#include<cstdio>#include<algorithm>#include<memory.h>#include<cmath>#include<queue>#define oo 2147483647using namespace std;  int v[n]; bool vis[n]; int dis[n]; int num; struct my {int x,y,l,ne;}e[m]; queue<int>q; void put(int x,int y,int l) {    num++;   e[num].x=x;   e[num].y=y;   e[num].l=l;   e[num].ne=v[x];   v[x]=num;  }void spfa()  {memset(vis,false,sizeof(vis));memset(dis,0x3f,sizeof(dis));vis[S]=1;dis[S]=0;q.push(S);while(!q.empty()){int x=q.front();vis[x]=0;q.pop();for(int i=v[x];i;i=e[i].ne){int y=e[i].y; if(dis[y]>dis[x]+e[i].l){dis[y]=dis[x]+e[i].l;    if(!vis[y])    {    q.push(y);    vis[y]=1;}}}}     vis[x]=0;    }