打算做 50 道 CF 的题目，并会附上题解。
1.CF995E Number Clicker
双向BFS+逆元
(Updated on 2021/3/9)
2.CF487E Tourists
点双连通分量+圆方树+树链剖分+splay
(Updated on 2021/4/16)
3.CF264B Good Sequences
线性筛质数+DP
(Updated on 2021/4/17)
4.CF587C Duff in the Army
树上倍增+LCA
(Updated on 2021/4/19)
5.CF786B Legacy
线段树+最短路
(Updated on 2021/5/15)
6.CF809D Hitchhiking in the Baltic States
splay+DP
(Updated on 2021/5/25)
7.CF818E Card Game Again
二分
(Updated on 2021/6/17)
8.CF1131F Asya And Kittens
链表+并查集
(Updated on 2021/7/8)
9.CF85D Sum of Medians
splay
(Updated on 2021/7/12)
10.CF609E Minimum spanning tree for each edge
LCA+最小生成树
(Updated on 2021/7/20)
11.CF609F Frogs and mosquitoes
线段树+二分
(Updated on 2021/7/20)