wpy的请求

代码如下：

#include<bits/stdc++.h>
using namespace std;
const int N=1e6+7;
int n,m,top,x[N],y[N],z[N],dis[N],head[N];
bool vis[N];
struct node{
    int too,next,zh;
}edge[N];
void add(int a,int b,int c)
{
    edge[++top].too=b;edge[top].zh=c;
    edge[top].next=head[a];head[a]=top;
}
void spfa()
{
    queue<int>q;
    q.push(0);
    while(!q.empty())
    {
        int u=q.front();q.pop();
        vis[u]=false;
        for(int i=head[u];i>=0;i=edge[i].next)
        {
            int v=edge[i].too;
            if(dis[v]>dis[u]+edge[i].zh)
            {
                dis[v]=dis[u]+edge[i].zh;
                if(!vis[v])
                {  
                    q.push(v);
                    vis[v]=true;
                }
            }
        }
    }
}
int main()
{

    memset(head,-1,sizeof(head));
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)dis[i]=1e9;
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&x[i],&y[i],&z[i]);
        add(x[i],y[i],z[i]);
    }
    for(int i=1;i<=n;i++)add(0,i,0);
    spfa();
    for(int i=1;i<=m;i++)
        printf("%d %d %d\n",x[i],y[i],dis[x[i]]+z[i]-dis[y[i]]);
    return 0;
}