简单反转，面向测试用例编程（
public class Solution { public static void main(String[] args) { Solution s = new Solution(); int[] arr = {1,2}; s.rotate(arr,0); } public void rotate(int[] nums, int k) { //排除特例 if(nums == null || nums.length == 0 || nums.length == 1) return; int num = k % nums.length; //排除特例 if(num == 0) return; reverse(nums,0,nums.length - 1); reverse(nums,0,num - 1); reverse(nums,num,nums.length - 1); // System.out.println(Arrays.toString(nums)); } public void reverse(int[] nums,int l,int r){ int mid = l + (r - l) / 2 + 1; for (int i = l; i < mid; i++) { int temp = nums[i]; nums[i] = nums[l + r -i]; nums[l + r - i] = temp; } } }