build建树时右儿子编号打错了
by A_Sunny_Day @ 2022-02-23 20:24:54
@[osfly](/user/339299)
```
void build(int k,int l,int r)
{
t[k].l=l;
t[k].r=r;
if(l==r) return ;
int mid=(l+r)/2;
build(2*k,l,mid);
build(2*k + 1,mid+1,r);
}
```
by happybob @ 2022-02-23 20:26:04