A subarray is any contiguous block of an array's elements. Given an array of integers, find the sum of all elements of all subarrays of that array. Example For example, a three element array [4, 5, 6] can be made into the following subarrays: 1 element subarrays: [4], [5], [6] 2 element subarrays: [4,5], [5,6] 3 element subarrays: [4, 5, 6] The sum of all subarrays is 4 + 5 + 6 + (4+5) + (5+6) +(4+5+6)=50. Function Description subarraySum has the following parameter(s): int arr[n]: an array of integers to process Returns: int: an integer representing the sum of all subarrays of the given array Constraints - 1 <= n <= 2× 105 - 1<=arr[i] ≤ 10^3, where 0 ≤ 7< n