旋转数组

class Solution {
    public void rotate(int[] nums, int k) {
        int length=nums.length;
        k%=length;
        reverse(nums,0,length-1-k);//先将数组全反转
        reverse(nums,length-k,length-1);//反转头k个
        reverse(nums,0,length-1);//反转k后面
    }
    public void reverse(int[] nums,int start,int end){
        while(start<end){
            int temp=nums[start];
            nums[start++]=nums[end];
            nums[end--]=temp;
        }
    }
}