B - traffic transformation

最小生成树问题.Think of intersections as points,Roads are treated as edge maps,The bare minimum spanning tree problem.

#include<bits/stdc++.h>
using namespace std;

const int N = 310;

struct stu{
    
	int u,v,c;
};

int f[N];

int find(int x)
{
    
	return f[x]==x?x:f[x]=find(f[x]);
}

void merge(int x,int y) 
{
    
	x=find(x),y=find(y);
    if(x==y) return;
    f[x]=y;
}

signed main()
{
    
	int n,m;cin>>n>>m;
	vector<stu> a(m);
	for(int i=0;i<m;i++)
	{
    
		int u,v,c;cin>>u>>v>>c;
		a[i]={
    u,v,c};
	}
	
	for(int i=0;i<n;i++) f[i]=i;
	
	sort(a.begin(),a.end(),[&](stu A,stu B){
    
		return A.c<B.c;
	});
	
	int sum=0,mx=0;
	for(int i=0;i<m;i++)
	{
    
		if(find(a[i].u)!=find(a[i].v))
		{
    
			merge(a[i].u,a[i].v);
			if(mx<a[i].c) mx=a[i].c;
			sum++;
		}
	}
	cout<<sum<<" "<<mx<<endl;
    return 0;
}