189. Rotate Array

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].

解答：K 如果大于length，对 k 求余

public class Solution {
    public int[] rotate(int[] nums, int k) {
        if(nums == null){
            return nums;
        }
        k = k % nums.length;
        reverse(nums, 0, nums.length - 1);
        reverse(nums, 0, k -1);
        reverse(nums, k, nums.length - 1);
        return nums;
    }

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

    }
}