codeforces#P1400D. Zigzags

    ID: 31402 远端评测题 2000ms 256MiB 尝试: 1 已通过: 1 难度: 6 上传者: 标签>brute forcecombinatoricsdata structuresmathtwo pointers*1900

Zigzags

Description

You are given an array $a_1, a_2 \dots a_n$. Calculate the number of tuples $(i, j, k, l)$ such that:

  • $1 \le i < j < k < l \le n$;
  • $a_i = a_k$ and $a_j = a_l$;

The first line contains a single integer $t$ ($1 \le t \le 100$) — the number of test cases.

The first line of each test case contains a single integer $n$ ($4 \le n \le 3000$) — the size of the array $a$.

The second line of each test case contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le n$) — the array $a$.

It's guaranteed that the sum of $n$ in one test doesn't exceed $3000$.

For each test case, print the number of described tuples.

Input

The first line contains a single integer $t$ ($1 \le t \le 100$) — the number of test cases.

The first line of each test case contains a single integer $n$ ($4 \le n \le 3000$) — the size of the array $a$.

The second line of each test case contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le n$) — the array $a$.

It's guaranteed that the sum of $n$ in one test doesn't exceed $3000$.

Output

For each test case, print the number of described tuples.

Samples

2
5
2 2 2 2 2
6
1 3 3 1 2 3
5
2

Note

In the first test case, for any four indices $i < j < k < l$ are valid, so the answer is the number of tuples.

In the second test case, there are $2$ valid tuples:

  • $(1, 2, 4, 6)$: $a_1 = a_4$ and $a_2 = a_6$;
  • $(1, 3, 4, 6)$: $a_1 = a_4$ and $a_3 = a_6$.