@[chlchl](/user/363036) 不是，哥们，你 $kth$ 的时候不$pushdown$ 是吧.
```cpp
int kth(int u, int k){
pushdown(u);
if(sz[son[u][0]] + 1 == k)
return u;
if(k <= sz[son[u][0]])
return kth(son[u][0], k);
return kth(son[u][1], k - sz[son[u][0]] - 1);
}
```
by junee @ 2024-07-29 20:57:22
@[junee](/user/757101) thx，傻了，已过
by chlchl @ 2024-07-29 20:59:32