# GeetCode Hub

Given an array of integers `arr` of even length `n` and an integer `k`.

We want to divide the array into exactly `n / 2` pairs such that the sum of each pair is divisible by `k`.

Return True If you can find a way to do that or False otherwise.

Example 1:

```Input: arr = [1,2,3,4,5,10,6,7,8,9], k = 5
Output: true
Explanation: Pairs are (1,9),(2,8),(3,7),(4,6) and (5,10).
```

Example 2:

```Input: arr = [1,2,3,4,5,6], k = 7
Output: true
Explanation: Pairs are (1,6),(2,5) and(3,4).
```

Example 3:

```Input: arr = [1,2,3,4,5,6], k = 10
Output: false
Explanation: You can try all possible pairs to see that there is no way to divide arr into 3 pairs each with sum divisible by 10.
```

Example 4:

```Input: arr = [-10,10], k = 2
Output: true
```

Example 5:

```Input: arr = [-1,1,-2,2,-3,3,-4,4], k = 3
Output: true
```

Constraints:

• `arr.length == n`
• `1 <= n <= 105`
• `n` is even.
• `-109 <= arr[i] <= 109`
• `1 <= k <= 105`

class Solution { public boolean canArrange(int[] arr, int k) { } }