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

Credits:
Special thanks to @Freezen for adding this problem and creating all test cases.

class Solution {public:    void rotate(int nums[], int n, int k) {   if(nums==NULL)   {   return ;   }     if(n<=0 || k<0)   {   return  ;   }      k=k%n;   int nBegin=0;   int nEnd=n-1;   while(nBegin<nEnd)   {   int nTemp=nums[nBegin];   nums[nBegin]=nums[nEnd];   nums[nEnd]=nTemp;   ++nBegin;   --nEnd;   }   nBegin=0;   nEnd=k-1;   while(nBegin<nEnd)   {   int nTemp=nums[nBegin];   nums[nBegin]=nums[nEnd];   nums[nEnd]=nTemp;   ++nBegin;   --nEnd;   }   nBegin=k;   nEnd=n-1;   while(nBegin<nEnd)   {   int nTemp=nums[nBegin];   nums[nBegin]=nums[nEnd];   nums[nEnd]=nTemp;   ++nBegin;   --nEnd;   }      }};