@[幻想繁星](/user/649095) 所以这题怎么做
by sto_5k_orz @ 2023-06-02 20:55:26
@[Stitch0711](/user/675466) LCA+树上差分
by 幻想繁星 @ 2023-06-02 20:56:11
@[Stitch0711](/user/675466) 代码您自己调吧，我要下课里力(抱歉）
by 幻想繁星 @ 2023-06-02 20:56:44
@[Stitch0711](/user/675466) 您好像只建了一个方向的边
by BitJump @ 2023-06-02 21:03:21
@[BitJump](/user/341323) 过了
by sto_5k_orz @ 2023-06-02 21:04:32
@[Stitch0711](/user/675466) 建双向边
by 5k_sync_closer @ 2023-06-02 21:05:44