qq_50808324的博客

题目链接：https://atcoder.jp/contests/abc202/tasks/abc202_eAtCoder Beginner Contest 202–E.Count Descendantsdfs序，二分拉在训练赛上做这题的时候头脑一热打了dfs序上主席树 ，但实际上此题挺巧妙的。题目大意为给定一棵有根树（1号节点为根），给定qqq个询问，每次询问节点uuu的子树中深度为ddd的节点个数（规定根节点深度为0）。题目给定的节点有两个特点：1.深度为ddd2.存在于节点uuu的子树中

题目描述Evlampiy has found one more cool application to process photos. However the application has certain limitations.Each photo i has a contrast vi. In order for the processing to be truly of high quality, the application must receive at least k photos w