NGCD - NO GCD
You are given N (1 <= N <= 100000) integers. Each integer is square free (meaning it has no divisor which is a square number except 1) and all the prime factors are less than 50. You have to find out the number of pairs are there such that their gcd is 1 or a prime number. Note that (i, j) and (j, i) are different pairs if i and j are different.
Input
The first line contains an integer T (1 <= T <= 10), the number of tests. Then T tests follows. First line of each tests contain an integer N. The next line follows N integers.
Output
Print T lines. In each line print the required result.
Example
Input: 1 3 2 1 6 Output: 8
Explanation
- gcd(1, 2) = 1
- gcd(2, 1) = 1
- gcd(2, 6) = 2, a prime number
- gcd(6, 2) = 2, a prime number
- gcd(1, 6) = 1
- gcd(6, 1) = 1
- gcd(2, 2) = 2, a prime number
- gcd(1, 1) = 1
So, total of 8 pairs.
Problem Setter: Nafis Sadique, Jahangirnagar University
Added by: | Alim |
Date: | 2016-04-01 |
Time limit: | 2s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ASM64 GOSU JS-MONKEY |