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].

Note:
Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.

[show hint]

Hint:
Could you do it in-place with O(1) extra space?

Related problem: Reverse Words in a String II

可以参考STL的rorate：

class Solution {
public:
    void rotate(vector<int>& nums, int k) {
        
        if(k == 0 || k > nums.size() && k % nums.size() == 0)
            return;
        
        k %= nums.size();

        reverse(nums.begin(), nums.end() - k);
        reverse(nums.end() - k, nums.end());
        reverse(nums.begin(), nums.end());

    }
};