189. 轮转数组

https://leetcode.cn/problems/rotate-array/

class Solution {
    public void rotate(int[] nums, int k) {
        int step = k % nums.length;
        int length = nums.length;
        reverse(nums, 0, length - 1);
        reverse(nums, 0, step - 1);
        reverse(nums, step, length -1);
    }
    private void reverse(int[] nums, int start, int end) {
        if (start == end) {
            return;
        }
        for (int i = start; i < (end - start)/2 + start; i++) {
            int temp = nums[i];
            nums[i] = nums[end - i];
            nums[end - i] = temp;
        }
    }
}