Til the cows Come Home

#include<iostream>
#include<queue>
#include<cstring>
#include<cstdio>
#define maxn 1002
using namespace std;
queue<int>q;
int head[maxn],dis[maxn],inq[maxn];
int sumedge,t,n,x,y,z;
 
struct Edge{
    int x,y,z,nxt;
    Edge(int x=0,int y=0,int z=0,int nxt=0):
        x(x),y(y),z(z),nxt(nxt){}
}edge[maxn<<2];

void add(int x,int y,int z){
    edge[++sumedge]=Edge(x,y,z,head[x]);
    head[x]=sumedge;
}

void spfa(){
    memset(dis,0x3f,sizeof(dis));
    dis[1]=0;inq[1]=1;q.push(1);
    while(!q.empty()){
        int now=q.front();q.pop();inq[now]=0;//经常忘了 
        for(int i=head[now];i;i=edge[i].nxt){
            int v=edge[i].y;
            if(dis[v]>dis[now]+edge[i].z){
                dis[v]=dis[now]+edge[i].z;
                if(!inq[v]){
                    inq[v]=1;q.push(v); 
                }
            }
        }
    } 
}

int main(){
    scanf("%d%d",&t,&n);
    for(int i=1;i<=t;i++){
        scanf("%d%d%d",&x,&y,&z);
        add(x,y,z);add(y,x,z);
    }
    spfa();
    printf("%d\n",dis[n]);
    return 0;
}