Rotate Array leetcode

Rotate an array of n elements to the right by k steps.

For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4].

采用三步翻转法

public class Solution {
    public void rotate(int[] nums, int k) {
        if (nums == null || nums.length == 0) {
            return;
        }
        int n = nums.length;
        if (k > n) {
            k = k%n;
        }
        rotate(nums, 0, n - k - 1);
        rotate(nums, n - k, n - 1);
        rotate(nums, 0, n - 1);
    }
    public void rotate(int[] nums, int left, int right) {
        if (left > right) {
            return;
        }
        int start = left;
        int end = right;
        while (start < end) {
            int tem = nums[start];
            nums[start] = nums[end];
            nums[end] = tem;
            start++;
            end--;
        }
    }
}