Codeforces
「思维+差分」CodeTON Round 2 (Div. 1 + Div. 2, Rated, Prizes!) D. Magical Array Solution
题目链接 题意：给定一个原数组b，和n个初始值和b …
「启发式合并+Set」Educational Codeforces Round 132 (Rated for Div. 2) E. XOR Tree Solution
题目链接 题意：给定一棵有点权的树，问最少多少次修 …
「LCA」Codeforces Round #805 (Div. 3) G2. Passable Paths (hard version) Solution
题目链接 题意：给定一棵n个节点的树，和q个询问， …
Educational Codeforces Round 125 (Rated for Div. 2) D. For Gamers. By Gamers.
本来是上大分的（之前状态有点萎靡，小号掉了一伯分） …
