Coprime ——鞍山C

TimeLimit: 2000/1000 MS (Java/Others)  MemoryLimit: 262144/262144 K (Java/Others)
64-bit integer IO format:%I64d
未提交 | 登录后收藏
Problem Description
There are n people standing in a line. Each of them has a unique id number.

Now the Ragnarok is coming. We should choose 3 people to defend the evil. As a group, the 3 people should be able to communicate. They are able to communicate if and only if their id numbers are pairwise coprime or pairwise not coprime. In other words, if their id numbers are a, b, c, then they can communicate if and only if [(a, b) = (b, c) = (a, c) = 1] or [(a, b) ≠ 1 and (a, c) ≠ 1 and (b, c) ≠ 1], where (x, y) denotes the greatest common divisor of x and y.

We want to know how many 3-people-groups can be chosen from the n people.
Input
The first line contains an integer T (T ≤ 5), denoting the number of the test cases.

For each test case, the first line contains an integer n(3 ≤ n ≤ 10 5), denoting the number of people. The next line contains n distinct integers a 1, a 2, . . . , a n(1 ≤ a i ≤ 10 5) separated by a single space, where a i stands for the id number of the i-th person.
Output
For each test case, output the answer in a line.
SampleInput
1
5
1 3 9 10 2
SampleOutput
4
Submit
题目统计信息详细
总AC数7
通过人数7
尝试人数12
总提交量27
AC率25.93%
AC该题后可以添加标签
贴完标签可以获得20ACB。
并且可以获得本题所有提交代码查看权限。
点击标题可以显示标签。
如果你还没认真思考过这题,请不要查看标签
如果您已经通过了该题,请务为该题贴上标签

T^T Online Judge

[BUG反馈] [FAQ] [闽ICP备17026590号-1]
当前版本:3.24 系统时间: