#189 Rotate Array.java

//https://leetcode.com/problems/rotate-array/
class Solution {
    public void rotate(int[] nums, int k) {
        k = k%nums.length;
        reverse(nums,0,nums.length-1);
        reverse(nums,0,k-1);
        reverse(nums,k,nums.length-1);
    }
    public void reverse(int[] nums, int start , int end) {
        while(start < end) {
            int tmp = nums[start];
            nums[start] = nums[end];
            nums[end] = tmp;
            start++;
            end--;
        }
    }
}