Difference between revisions of "ACM-ICPC 2018 Xuzhou Online Contest"
Jump to navigation
Jump to search
| Line 16: | Line 16: | ||
Solved by zerol. 00:59 (+2) | Solved by zerol. 00:59 (+2) | ||
| + | |||
| + | 题意：求 $\sum_{i=1}^m \mu(in)$ | ||
| + | |||
| + | 题解：如果 $n$ 中有平方因子，那么显然答案是 0。否则相当于求 $\mu(n) \cdot \sum_{i=1}^m \mu'(i)$，其中 $\mu'$ 是在 $\mu$ 的基础上不把 $n$ 的质因数当质数。类似于求 $\mu$ 的前缀和的方法（任意一种亚线性筛），改一改就能过了。 | ||
== Problem E == | == Problem E == | ||
Revision as of 09:54, 9 September 2018
ECNU Foreigners
Problem A
Solved by ultmaster. 01:19 (+)
Problem B
Solved by kblack. 01:16 (+1)
Problem C
Solved by ultmaster. 02:56 (+2)
Problem D
Solved by zerol. 00:59 (+2)
题意：求 $\sum_{i=1}^m \mu(in)$
题解：如果 $n$ 中有平方因子，那么显然答案是 0。否则相当于求 $\mu(n) \cdot \sum_{i=1}^m \mu'(i)$，其中 $\mu'$ 是在 $\mu$ 的基础上不把 $n$ 的质因数当质数。类似于求 $\mu$ 的前缀和的方法（任意一种亚线性筛），改一改就能过了。
Problem E
Problem F
Solved by ultmaster. 00:26 (+)
Problem G
Solved by kblack. 00:34 (+)
Problem H
Solved by zerol. 01:16 (+)
Problem I
Solved by kblack. 00:16 (+)
Problem J
Solved by kblack. 02:42 (+3)
Problem K
Solved by zerol. 02:51 (+6)