```cpp
else if (op == 1){
read(lto, rto); lfrom = l, rfrom = r;
k = rfrom - lfrom + 1; k -= sum(1, 1, n, lfrom, rfrom); modify(1, 1, n, lfrom, rfrom, 1); // 在这里特判 k = 0
if (lto>1) s = sum(1, 1, n, 1, lto-1);
else s = 0;
pos = Find(1, 1, n, s + k);
modify(1, 1, n, lto, min(rto, pos), 0); // 否则这里仍然执行修改导致错误，宾且这里特判 lto <= min(...) 也没用，因为可能 lto = 1（数据好毒啊！！）
}
```
by wangsiyuanZP @ 2024-02-22 12:35:10
@[wangsiyuanZP](/user/255436) 卷!
by tzl_Dedicatus545 @ 2024-02-22 13:01:33