这个代码WA on #9 我下了数据，本地运行结果和洛谷一模一样，但就是WA了，什么原理？？？

#include <bits/stdc++.h>
using namespace std;
const int MAXN=3000005;
int n,m;
struct A{
	int id,dis;
	bool operator<(const A &_)const{
		return dis>_.dis;
	}
};
struct B{
	int v,w;
};
priority_queue<A,vector<A> > q;
vector<B> e[MAXN];
int dis[MAXN],xx[2];
bool vis[MAXN],qq[2005][2005];
long long cnt[MAXN];
void dij(){
	memset(dis,0x3f,sizeof(dis));
	memset(xx,0x3f,sizeof(xx));
	dis[1]=0;
	cnt[1]=1;
	q.push(A{1,0});
	while(!q.empty()){
		int u=q.top().id;
		q.pop();
		if(vis[u])continue;
		vis[u]=1;
		for(int i=0;i<e[u].size();i++){
			int v=e[u][i].v;
			int w=e[u][i].w;
			if(!vis[v]&&dis[u]+w<dis[v]){
				dis[v]=dis[u]+w;
				q.push(A{v,dis[v]});
				cnt[v]=cnt[u];
			}else if(!vis[v]&&dis[u]+w==dis[v]){
				cnt[v]+=cnt[u];
			}
		}
	}
}
int main() {
	cin>>n>>m;
	while(m--){
		int x,y,w;
		cin>>x>>y>>w;
		if(qq[x][y]){
		    for(int i = 0 ; i < e[x].size() ; i++)if(e[x][i].v==y) e[x][i].w=min(e[x][i].w,y);
			continue ;
		}
		qq[x][y]=1 ;
		e[x].push_back(B{y,w});
	}
	dij();
	if(dis[n]==xx[1])cout << "No answer" << "\n";
	else cout << dis[n] << " " << cnt[n] << "\n";
	return 0;
}