Live2d Test Env
2018年12月31日
CF1096.F. Inversion Expectation(树状数组)
摘要： A permutation of size n is an array of size n such that each integer from 1 to n occurs exactly once in this array. An inversion in a permutation p is 阅读全文
posted @ 2018-12-31 15:54 nimphy 阅读(356) 评论(0) 推荐(0) 编辑