摘要: 2020杭电多校第六场 7. A Very Easy Math Problem 题意: 求 \[ \sum_{a_1=1}^n\sum_{a_2=1}^n...\sum_{a_x=1}^n(\prod_{j=1}^xa_j^k)f(gcd(a_1,a_2,...,a_x))*gcd(a_1,a_2, 阅读全文
posted @ 2020-08-06 17:04 zhaoxiaoyun 阅读(442) 评论(0) 推荐(1) 编辑