本题轮转数组，其实反转三次就行了
class Solution {
int nums[];
int k;
public void rotate(int[] nums, int k) {
if(k>=nums.length){
k=k%nums.length;
}
this.nums= nums;
this.k = k;
int bounder = nums.length-k;
reverse(0,bounder-1);
reverse(bounder,nums.length-1);
reverse(0,nums.length-1);
}
public void reverse(int start,int end){
while(start<end){
int temp = nums[start];
nums[start] = nums[end];
nums[end] = temp;
end--;
start++;
}
}
}