2019年8月9日
permutation 1 多校第五场
摘要： Problem Description A sequence of length n is called a permutation if and only if it's composed of the first n positive integers and each number appea 阅读全文
posted @ 2019-08-09 14:17 -第4题- 阅读(260) 评论(0) 推荐(0) 编辑