spfa模板

#include <cstdio>
#include <cstring>
#include <iostream>
#include <queue>
#include <map>
#include <vector>
using namespace std;
const int maxn=100010;
const int inf=0x3f3f3f3f;
int n,m;
struct node
{
    int x,cost;
};
vector<node> edge[100010];
int spfa(int s)
{
    int vis[maxn];
    int d[maxn];
    queue<int> q;
    memset(vis,0,sizeof(vis));
    fill(d,d+maxn,inf);
    vis[s]=1; // means s in the queue
    d[s]=0;
    q.push(s); //
    while(!q.empty())
    {
        int now=q.front();
        q.pop();
        vis[now]=0;
        for(int i=0;i<edge[now].size();i++)
        {
            node temp=edge[now][i];
            if(d[temp.x] > d[now]+temp.cost)
            {
                d[temp.x]=d[now]+temp.cost;
                if(vis[temp.x]==0)
                {
                    vis[temp.x]=1; //
                    q.push(temp.x);
                }
            }
        }
    }
    return d[n];
}
int main()
{
    while(cin>>n>>m)
    {
        if(n==0 || m==0) break;
        for(int i=0;i<=n;i++) edge[i].clear();
        while(m--)
        {
            int a,b,cost;
            scanf("%d %d %d",&a,&b,&cost);
            node temp;
            temp.cost=cost;
            temp.x=a;
            edge[b].push_back(temp);
            temp.x=b;
            edge[a].push_back(temp);
        }
        cout<<spfa(1)<<endl;
    }

    return 0;
}