Codeforces Round /#683 (Div. 1) B.Catching Cheaters(DP最大子段和+LCS) 2020-11-17 ACM Codeforces Round /#679 (Div. 2) C.Perform Easily(二分/集合) 2020-10-28 ACM Codeforces Round /#676 (Div. 2) D. Hexagons 题解 2020-10-20 ACM