MrBlank的ACM记事本

Drainage Ditches Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 70372 Accepted: 27358 DescriptionEvery time it rains on Farmer John’s fields, a pond forms over Bessie’s favor

Power Network Time Limit: 2000MS Memory Limit: 32768K Total Submissions: 27278 Accepted: 14176 DescriptionA power network consists of nodes (power stations, consumers and dispatchers) co

有向无环图 Time Limit: 5000MS Memory Limit: 131072KB 64bit IO Format: %lld & %llu SubmitStatusDescription Bobo 有一个 n 个点，m 条边的有向无环图（即对于任意点 v，不存在从点 v 开始、点 v 结束的路径）。 为了方便，点用 1,2,…,n 编号。 设 count(x