题目描述
There was a power value associated with each soldier of Ram’s troop. It was a known belief that if two soldiers could be paired such that their total power can be divided by 3 perfectly, the pairing becomes ultra-powerful. Ram was curious as to see how many such pairings were possible.
Help Ram find out the number of pairings(not necessarily unique) possible from his troop.
INPUT:
An integer T (1 ≤ T ≤ 1000) : number of testcases
Each test case is represented by a number N(1 ≤ N ≤ 100) denoting the number of soldiers followed by an unordered list of N values representing the soldier’s power P(1 ≤ P ≤ 10000).
OUTPUT:
For each test case T, output the value of number of possible pairs from the given list such that the sum of the values in each pair is a multiple of 3.
SAMPLE INPUT
3
5
3 6 7 2 9
4
2 1 3 4
3
9 9 9
SAMPLE OUTPUT
4
2
3
Explanation
In the first test case, the groups are (3,6),(3,9),(9,6),(7,2).
In the second test case, the groups are (2,1),(2,4)
In the third test case, the groups are (9,9),(9,9),(9,9))
输入格式
见题面
输出格式
见题面