本地评测机能过，提交WA，玄一关

#include<bits/stdc++.h>
using namespace std;
int n,m,sum;
bool book[5010];
vector<int>e[5010];
vector<int>w[5010];
priority_queue<pair<int,int> >q;
int main()
{
	scanf("%d%d",&n,&m);
	for(int i=1;i<=m;i++)
	{
		int u,v,ww;
		scanf("%d%d%d",&u,&v,&ww);
		e[u].push_back(v);
		w[u].push_back(ww);
		e[v].push_back(u);
		w[v].push_back(ww);
	}
	book[1]=1;
	for(int i=0;i<e[1].size();i++)
	{
		q.push(make_pair(e[1][i],w[1][i]));
	}
	while(!q.empty())
	{
		int vv=q.top().first;
		int ww=q.top().second;
		if(book[vv]==1)
		{
			q.pop();
			continue;
		}
		book[vv]=1;
		for(int i=0;i<e[vv].size();i++)
		{
			q.push(make_pair(e[vv][i],w[vv][i]));
		}
		sum+=ww;
		q.pop();
	}
	cout<<sum;
	return 0;
}

5 18
2 4 276
3 3 435
3 4 608
2 4 860
1 2 318
1 3 547
5 4 419
2 5 98
1 5 460
5 3 399
3 5 240
3 2 733
3 3 903
4 2 909
5 2 206
3 4 810
2 1 115
2 3 419

729