题目描述
Highway 201 is the most busy street in Rockport. Traffic cars cause a lot of hindrances to races, especially when there are a lot of them. The track which passes through this highway can be divided into $n$ sub-tracks. You are given an array $a$ where $a_i$ represents the number of traffic cars in the $i$-th sub-track. You define the inconvenience of the track as $\sum\limits_{i=1}^{n} \sum\limits_{j=i+1}^{n} \lvert a_i-a_j\rvert$, where $|x|$ is the absolute value of $x$.
You can perform the following operation any (possibly zero) number of times: choose a traffic car and move it from its current sub-track to any other sub-track.
Find the minimum inconvenience you can achieve.
Input
The first line of input contains a single integer $t$ ($1\leq t\leq 10\,000$) — the number of test cases.
The first line of each test case contains a single integer $n$ ($1\leq n\leq 2\cdot 10^5$).
The second line of each test case contains $n$ integers $a_1, a_2, \ldots, a_n$ ($0\leq a_i\leq 10^9$).
It is guaranteed that the sum of $n$ over all test cases does not exceed $2\cdot 10^5$.
Output
For each test case, print a single line containing a single integer: the minimum inconvenience you can achieve by applying the given operation any (possibly zero) number of times.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
For the first test case, you can move a car from the $3$-rd sub-track to the $1$-st sub-track to obtain $0$ inconvenience.
For the second test case, moving any car won't decrease the inconvenience of the track.