rt，不知道哪里错了

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int size=2050;
const int inf=0x3f3f3f3f3f3f3f3f;
int n,m,ans=inf;
int dis[size][size],mp[size][size];
signed main(){
	ios::sync_with_stdio(0);
	cin>>n>>m;
	memset(dis,0x3f,sizeof(dis));
	memset(mp,0x3f,sizeof(mp));
	for(int i=1;i<=n;++i) mp[i][i]=dis[i][i]=0;
	for(int i=1;i<=m;++i){
		int u,v,w;
		cin>>u>>v>>w;
		dis[u][v]=min(dis[u][v],w);dis[v][u]=min(dis[v][u],w);
		mp[u][v]=min(mp[u][v],w);mp[v][u]=min(mp[v][u],w);
	}
	for(int k=1;k<=n;++k){
		for(int i=1;i<k;++i) for(int j=i+1;j<k;++j) ans=min(ans,dis[i][j]+mp[k][j]+mp[i][k]);
		for(int i=1;i<=n;++i) for(int j=1;j<=n;++j) dis[i][j]=dis[j][i]=min(dis[i][j],dis[i][k]+dis[k][j]);
	}
	if(ans==inf) cout<<"No solution.";
	else cout<<ans<<endl;
	return 0;
}

read - , expected 3
read - , expected 1