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.
Credits:
Special thanks to @Freezen for adding this problem and creating all test cases.
原文：http://www.cnblogs.com/zgcy123456/p/4300366.html