Given an array of random integers, find subarray such that sum of elements in the element is divisible by k.

For example, For A=[2, -3, 5, 4, 3, -1, 7]. The for k = 3 there is a subarray for example {-3, 5, 4}. For, k=5 there is subarray {-3, 5, 4, 3, -1, 7} etc.