「Edu Codeforces Round」#134

「NowCoder Round X」#56

「NowCoder Round X」#55

「Codeforces Round」#816 (Div 2)

「Codeforces Round」#814 (Div 2)

「Codeforces Round」#813 (Div 2)

NowCoderX54F 题解

「Codeforces Round」#812 (Div 2)

「Edu Codeforces Round」#133 (Div 2)

「Codeforces Round」#806 (Div 4)