Codeforces Round #599 (Div. 2) B2. Character Swap (Hard Version) 构造
B2. Character Swap (Hard Version) This problem is different from the easy version. In this version ...
B2. Character Swap (Hard Version) This problem is different from the easy version. In this version ...
F. Equalizing Two Strings You are given two strings s and t both of length n and both consisting of ...