这不是板子题吗,我怎么写挂了？

#include<bits/stdc++.h>
#define int long long
using namespace std;
typedef pair<int,int>PII;
const int N=1e5+10;
const int inf=0x3f3f3f3f;
struct edge{int v,s;};
vector<edge>e[N];
int dis[N];
void solve()
{
	int n,m;
	cin>>n>>m;
	for(int i=1;i<=m;i++)
	{
		int a,b,c;
		cin>>a>>b>>c;
		e[a].push_back({b,c});
		e[b].push_back({a,c});
	}
	int ans=0;
	vector<bool>vis(N,false);
	auto prim=[&](int x)
	{
        priority_queue<PII>q;
        for(int i=0;i<=n;i++)dis[i]=inf;
        dis[x]=0;
        q.push({0,x});
        while(q.size())
        {
        	auto t=q.top();q.pop();
        	int u=t.second;
        	if(vis[u])continue;
        	vis[u]=true;
        	if(dis[u]!=inf)ans=max(ans,dis[u]);
        	for(auto y:e[x])
        	{ 
        		int v=y.v,s=y.s;
        		if(dis[v]>s)
        		{
        			dis[v]=s;
        			q.push({-dis[v],v});
        		}
        	}
        }
	};
	prim(1);
	cout<<ans;
}
signed main()
{
	ios::sync_with_stdio(false);
	cin.tie(0),cout.tie(0);
	solve();
	return 0;
}