没判输出orz的情况，应该还有其他错
by sherry_lover @ 2024-07-04 15:29:34
fa[a[i].las]=a[i].fir;应改为fa[fa_las] = a[i].fir;
by sherry_lover @ 2024-07-04 15:32:57
@[sherry_lover](/user/686281) 还有什么错？求助
by glass_goldfish @ 2024-07-04 15:34:28
不应该是 `fa[fa_fir]=fa_las;` 吗
by aCssen @ 2024-07-04 15:37:21
@[aCssen](/user/534296) 对
by sherry_lover @ 2024-07-04 15:39:08
@[sherry_lover](/user/686281) @[aCssen](/user/534296) 最后一个点怎么办
by glass_goldfish @ 2024-07-04 15:40:40
@[aCssen](/user/534296) @[sherry_lover](/user/686281)
最后一个点数据：
```
in:
5 6
1 2 3
2 3 4
3 1 4
4 5 6
5 4 6
1 3 5
out:
orz
```
by glass_goldfish @ 2024-07-04 15:43:03
到最后 $cnt$ 还没到 $n-1$ 就输出 `orz`。
by aCssen @ 2024-07-04 15:50:08
@[aCssen](/user/534296)
```cpp
#include<bits/stdc++.h>
using namespace std;
struct bian{long long fir,las,qz;}a[1000001];
long long n,x;
bool cmp(bian a,bian b){return a.qz<b.qz;}
long long cnt,ans;
long long fa[1000001];
long long fi(long long p){if(p==fa[p])return p;else return fi(fa[p]);}
int main()
{
cin>>n>>x;
for(long long i=1;i<=n;i++)
fa[i]=i;
for(long long i=1;i<=x;i++)
cin>>a[i].fir>>a[i].las>>a[i].qz;
sort(a+1,a+x+1,cmp);
for(long long i=1;;i++){
if(cnt==n-1)break;
long long fa_fir=fi(a[i].fir);
long long fa_las=fi(a[i].las);
if(fa_fir==fa_las)continue;
fa[fa_fir]=fa_las;
ans+=a[i].qz;
cnt++;
}
if(cnt+1!=n)cout<<"orz";//if(cnt+1<n)cout<<"orz";也是一样的结果
else cout<<ans;
return 0;
}//84pts,WA最后#13
```
by glass_goldfish @ 2024-07-04 15:54:39
@[liulijinyu](/user/1328469) 忘说了，枚举边的循环 $i$ 是不能超过 $x$，就是说要这么写
```cpp
for(long long i=1;i<=x;i++){
long long fa_fir=fi(a[i].fir);
long long fa_las=fi(a[i].las);
if(fa_fir==fa_las)continue;
fa[a[i].las]=a[i].fir;
ans+=a[i].qz;
cnt++;
if(cnt==n-1)break;//这是为了考虑最后一条边
}
```
by aCssen @ 2024-07-04 15:58:48