????
by c_subtract_subtract @ 2024-10-29 18:15:15
@[Small_Traveler](/user/565852)
感谢大佬
by dapipi3878 @ 2024-10-29 18:15:47
代码顺便发：
```cpp
#include<iostream>
#include<algorithm>
#define int long long
using namespace std;
const int N=1e7;
int n,m,f[N],ans;
struct Node{int u,v,n;}a[N*10];
int find(int x){return f[x]==x?x:f[x]=find(f[x]);}
void unit(int x,int y){f[find(x)]=find(y);}
bool cmp(Node x,Node b){return x.n<b.n;}
signed main()
{
cin>>n>>m;
for(int i=1;i<=n;i++) f[i]=i;
for(int i=1;i<=m;i++) cin>>a[i].u>>a[i].v>>a[i].n;
sort(a,a+m+1,cmp);
int cnt=0;
for(int i=1;i<=m;i++)
{
int x=find(a[i].u),y=find(a[i].v);
if(x!=y)
{
ans+=a[i].n;
f[y]=x;
cnt++;
unit(x,y);
}
if(cnt==n-1) break;
}
if(cnt!=n-1) cout<<"orz";
else cout<<ans;
}
```
by c_subtract_subtract @ 2024-10-29 18:16:06