[link](https://www.luogu.com.cn/record/43803014)
```cpp
void Solve(int u,int L=1,int R=k){
int mid=L+R>>1,Prean=top;
for(int&now:t[u]){
int x=e[now].u,y=e[now].v,tx=Find(x),ty=Find(y);
if(tx!=ty)Merge(x,y+n),Merge(x+n,y);
else{
for(register int i=L;i<=R;++i)printf("No\n");
return pop(Prean);
}
}
if(L==R)printf("Yes\n");
else Solve(u<<1,L,mid),Solve(u<<1|1,mid+1,R),pop(Prean);
}
```
在递归到底层时未撤消操作，70pts
@[chen_zhe](/user/8457)
by Prean @ 2020-12-17 12:45:54
qp
by Tony2 @ 2020-12-17 12:50:25
qpee
by 滑大稽 @ 2020-12-17 12:54:27
大艹
by Eason_AC @ 2020-12-17 14:03:26
pop Prean，豌豆射手！
by peterwuyihong @ 2021-11-09 19:53:05
/bx 我就是这错了，调了一晚上。
by c1120241919 @ 2023-09-26 22:54:21
@[c1120241919](/user/686053) %%%
by yz_by @ 2023-10-01 13:08:06