【Codeforces1187F】Expected Square Beauty 发表于 2019-07-04 https://codeforces.com/contest/1187/problem/F 阅读全文 »
【Codeforces 908H】 New year and Boolean Bridges 发表于 2019-06-18 http://codeforces.com/problemset/problem/908/H 阅读全文 »