摘要: HDU-3664 Permutation Counting Given a permutation a1, a2, … aN of {1, 2, …, N}, we define its E-value as the amount of elements where ai > i. For exam 阅读全文
posted @ 2018-08-28 17:00 *starry* 阅读(120) 评论(0) 推荐(0) 编辑