kruscal

#include<bits/stdc++.h>
using namespace std;
const int maxn=2e5+10;
int fi[maxn],ne[maxn],v[maxn],w[maxn];
struct re
{
	int x,y,z;
};
re a[maxn];
int fa[maxn];
int t=-1;

bool cmp(re a,re b)
{
	return a.z<b.z;
}
int find(int k)
{
	if (k==fa[k]) return k;
	else return fa[k]=find(fa[k]);
}
int main()
{
	int n,m;
	cin>>n>>m;
	for (int i=1;i<=n;i++) fa[i]=i;
	for (int i=1;i<=m;i++)
	{		
		scanf("%d%d%d",&a[i].x,&a[i].y,&a[i].z);
	}
	sort(a+1,a+1+m,cmp);	
	int ans=0;
	int mark=0;
	for (int i=1;i<=m;i++)
	{
		if (find(a[i].x)==find(a[i].y)) continue;
		ans+=a[i].z;
		fa[find(a[i].x)]=find(a[i].y);
		mark++;
		if (mark==n-1) break;
	}
	if (mark!=n-1) cout<<"orz";else cout<<ans;	
}