摘要：Codeforces 382E Ksenia and CombinatoricsKsenia has her winter exams. Today she is learning combinatorics. Here’s one of the probl... 阅读全文

摘要：Codeforces 15E TrianglesLast summer Peter was at his granny’s in the country, when a wolf attacked sheep in the nearby forest. No... 阅读全文

摘要：Codeforces 932E Team work You have a team of N people. For a particular task, you can pick any non-empty subset of people. The cost of having x people 阅读全文