Codeforces Round 837 (Div. 2)
A
Hossam and Combinatorics
Codeforces
900
原题
←B →
翻译中…

Hossam woke up bored, so he decided to create an interesting array with his friend Hazem.

翻译中…

Now, they have an array $a$ of $n$ positive integers, Hossam will choose a number $a_i$ and Hazem will choose a number $a_j$.

翻译中…

Count the number of interesting pairs $(a_i, a_j)$ that meet all the following conditions:

翻译中…
  • $1 \le i, j \le n$;
  • $i \neq j$;
  • The absolute difference $|a_i - a_j|$ must be equal to the maximum absolute difference over all the pairs in the array. More formally, $|a_i - a_j| = \max_{1 \le p, q \le n} |a_p - a_q|$.
翻译中…

Input

翻译中…

The input consists of multiple test cases. The first line contains a single integer $t$ ($1 \le t \le 100$), which denotes the number of test cases. Description of the test cases follows.

翻译中…

The first line of each test case contains an integer $n$ ($2 \le n \le 10^5$).

翻译中…

The second line of each test case contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^5$).

翻译中…

It is guaranteed that the sum of $n$ over all test cases does not exceed $10^5$.

翻译中…

Output

翻译中…

For each test case print an integer — the number of interesting pairs $(a_i, a_j)$.

翻译中…

Note

翻译中…

In the first example, the two ways are:

翻译中…
  • Hossam chooses the fourth number $8$ and Hazem chooses the fifth number $1$.
  • Hossam chooses the fifth number $1$ and Hazem chooses the fourth number $8$.
翻译中…

In the second example, the four ways are:

翻译中…
  • Hossam chooses the second number $2$ and Hazem chooses the sixth number $10$.
  • Hossam chooses the sixth number $10$ and Hazem chooses the second number $2$.
  • Hossam chooses the fifth number $2$ and Hazem chooses the sixth number $10$.
  • Hossam chooses the sixth number $10$ and Hazem chooses the fifth number $2$.
翻译中…

样例

Input #1
2
5
6 2 3 8 1
6
7 2 8 3 2 10
Output #1
2
4
InputCopy OutputCopy
题目信息
题号
1771A
时间限制
2 s
内存限制
256 MB
标签
组合数学
数学
排序

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。