随笔分类 -  容斥原理

codeforces 839D (推公式+容斥原理/莫比乌斯函数）
摘要：Winter is here at the North and the White Walkers are close. John Snow has an army consisting of n soldiers. While the rest of the world is fi... 阅读全文
posted @ 2017-09-19 21:18 黑码的博客 阅读(290) 评论(0) 推荐(0)