189. 旋转数组

class Solution 
{
public:
    void rotate(vector<int>& nums, int k) 
    {
        int n = nums.size();
        k = k % n;
        reverse(nums.begin(),nums.begin() + n - k);
        reverse(nums.begin() + n - k,nums.end());
        reverse(nums.begin(),nums.end());
    }
};