Given an unsorted array arr[] of size N. Rotate the array to the left (counter-clockwise direction) by D steps, where D is a positive integer.

Example 1:
Input:
N = 5, D = 2
arr[] = {1,2,3,4,5}
Output: 3 4 5 1 2
Explanation: 1 2 3 4 5 when rotated
by 2 elements, it becomes 3 4 5 1 2.
Example 2:
Input:
N = 10, D = 3
arr[] = {2,4,6,8,10,12,14,16,18,20}
Output: 8 10 12 14 16 18 20 2 4 6
Explanation: 2 4 6 8 10 12 14 16 18 20
when rotated by 3 elements, it becomes
8 10 12 14 16 18 20 2 4 6.

Your Task:
Complete the function rotateArr() which takes the array, D and N as input parameters and rotates the array by D elements. The array must be modified in-place without using extra space.

Expected Time Complexity: O(N)
Expected Auxiliary Space: O(1)

Constraints:
1 <= N <= 10^{6}
1 <= D <= 10^{6}
0 <= arr[i] <= 10^{5}

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