echozqn:
博客地址:https://www.cnblogs.com/echozqn/
echozqn:
博客地址:https://www.cnblogs.com/echozqn/
D. Equalize the Remainders set的使用+思维
H. Subsequences (hard version) dp
E. Sasha and Array 矩阵快速幂 + 线段树
E. XOR Guessing 交互题 Educational Codeforces Round 71 (Rated for Div. 2)
C. Helga Hufflepuff's Cup 树形dp 难
B - Save the problem! CodeForces - 867B 构造题
Codeforces Round #546 (Div. 2) C. Nastya Is Transposing Matrices
cf 20190307 Codeforces Round #543 (Div. 2, based on Technocup 2019 Final Round)