有点懵
#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;
}