[Leetcode] 189. Rotate Array

189. 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]
Related problem: Reverse Words in a String II
Credits:Special thanks to @Freezen for adding this problem and creating all test cases.

class Solution {
public:
    void rotate(vector<int>& nums, int k) {
        int n = nums.size();
        k=k%n;
        reverse(nums,0,n-k-1);
        reverse(nums,n-k,n-1);
        reverse(nums,0,n-1);
    }
private:
    void reverse(vector<int>& nums,int low, int high) {
        while(low <= high){
            swap(nums[low], nums[high]);
            low++;
            high--;
        }
    }
};