#P1535B. Array Reodering
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ID: 5957
Type: RemoteJudge
2000ms
256MiB
Tried: 0
Accepted: 0
Difficulty: (None)
Uploaded By:
Hydro
Tags> Array Reodering
No submission language available for this problem.
Description
You are given an array $a$ consisting of $n$ integers.
Let's call a pair of indices $i$, $j$ good if $1 \le i < j \le n$ and $\gcd(a_i, 2a_j) > 1$ (where $\gcd(x, y)$ is the greatest common divisor of $x$ and $y$).
Find the maximum number of good index pairs if you can reorder the array $a$ in an arbitrary way.
The first line contains a single integer $t$ ($1 \le t \le 1000$) — the number of test cases.
The first line of the test case contains a single integer $n$ ($2 \le n \le 2000$) — the number of elements in the array.
The second line of the test case contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^5$).
It is guaranteed that the sum of $n$ over all test cases does not exceed $2000$.
For each test case, output a single integer — the maximum number of good index pairs if you can reorder the array $a$ in an arbitrary way.
Input
The first line contains a single integer $t$ ($1 \le t \le 1000$) — the number of test cases.
The first line of the test case contains a single integer $n$ ($2 \le n \le 2000$) — the number of elements in the array.
The second line of the test case contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^5$).
It is guaranteed that the sum of $n$ over all test cases does not exceed $2000$.
Output
For each test case, output a single integer — the maximum number of good index pairs if you can reorder the array $a$ in an arbitrary way.
Samples
3
4
3 6 5 3
2
1 7
5
1 4 2 4 1
4
0
9
Note
In the first example, the array elements can be rearranged as follows: $[6, 3, 5, 3]$.
In the third example, the array elements can be rearranged as follows: $[4, 4, 2, 1, 1]$.