@[DOs__lx](/user/261006)
find建议这么写
```cpp
return fa[x]==x?x:fa[x]=find(fa[x]);
```
by Smile_Cindy @ 2020-02-16 12:24:06
把find里的while换成if试试？
by Xhesika_Frost @ 2020-02-16 12:24:50
@[DOs__lx](/user/261006) 您的双向边呢
by 良知 @ 2020-02-16 12:25:55
kruskal要啥双向边。。。。
by jerry3128 @ 2020-02-16 12:34:51
@[DOs__lx](/user/261006) 因为你写错了
by cnyzz @ 2020-02-16 12:35:30
@[DOs__lx](/user/261006) 建议在学学并查集……
by __gcd @ 2020-02-16 12:35:50
```
inl int find(int x){
if(x == fa[x])
{
return x;
}
return fa[x] = find(fa[x]);
}
```
by __gcd @ 2020-02-16 12:36:52
并查集都是楼上那么写的吧
~~~
int find(int x){ return x == fa[x] ? x : fa[x] = find(fa[x]) ; }
by 1saunoya @ 2020-02-16 12:37:51
启发式合并：
```cpp
void unionn(int x,int y){
int fx=find(x),fy=find(y);
if(fx==fy) return;
if(size[fx]<=size[fy]){
size[fy]+=size[fx];
father[fx]=fy;
}
else{
size[fx]+=fy;
father[fy]=fx;
}
return;
}
```
by raincity @ 2020-02-16 12:48:53
蟹蟹各位大佬，现在A了
by DOs__lx @ 2020-02-16 12:50:20