Array Rotation

Use array reversal for array rotation .
Use two pointer for array reversal.

public class Solution {
public void Rotate(int[] nums, int k) {
k=k% nums.Length;
k=k% nums.Length;
reverse(nums, 0, nums.Length-1);
reverse(nums,0, k-1);
reverse(nums,k,nums.Length-1);
}

void reverse(int[] nums, int start , int end)
{
    while(start<end)
    {
        int temp=nums[start];
        nums[start]=nums[end];
        nums[end]=temp;
        start++;
        end--;
    }
}

}