old_contents: """Leetcode 189. Rotate Array
  Easy
  
  URL: https://leetcode.com/problems/rotate-array/
  
  Given an array, rotate the array to the right by k steps, where k is non-negative.
  
  Example 1:
  Input: [1,2,3,4,5,6,7] and k = 3
  Output: [5,6,7,1,2,3,4]
  Explanation:
  rotate 1 steps to the right: [7,1,2,3,4,5,6]
  rotate 2 steps to the right: [6,7,1,2,3,4,5]
  rotate 3 steps to the right: [5,6,7,1,2,3,4]
  
  Example 2:
  Input: [-1,-100,3,99] and k = 2
  Output: [3,99,-1,-100]
  Explanation: 
  rotate 1 steps to the right: [99,-1,-100,3]
  rotate 2 steps to the right: [3,99,-1,-100]
  
  Note:
  - Try to come up as many solutions as you can, 
    there are at least 3 different ways to solve this problem.
  - Could you do it in-place with O(1) extra space?
  """
  
  class Solution(object):
      def rotate(self, nums, k):
          """
          :type nums: List[int]
          :type k: int
          :rtype: None Do not return anything, modify nums in-place instead.
          """
          pass
  
  
  def main():
      pass
  
  
  if __name__ == '__main__':
      main()
  
new_contents: """Leetcode 189. Rotate Array
  Easy
  
  URL: https://leetcode.com/problems/rotate-array/
  
  Given an array, rotate the array to the right by k steps, where k is non-negative.
  
  Example 1:
  Input: [1,2,3,4,5,6,7] and k = 3
  Output: [5,6,7,1,2,3,4]
  Explanation:
  rotate 1 steps to the right: [7,1,2,3,4,5,6]
  rotate 2 steps to the right: [6,7,1,2,3,4,5]
  rotate 3 steps to the right: [5,6,7,1,2,3,4]
  
  Example 2:
  Input: [-1,-100,3,99] and k = 2
  Output: [3,99,-1,-100]
  Explanation: 
  rotate 1 steps to the right: [99,-1,-100,3]
  rotate 2 steps to the right: [3,99,-1,-100]
  
  Note:
  - Try to come up as many solutions as you can, 
    there are at least 3 different ways to solve this problem.
  - Could you do it in-place with O(1) extra space?
  """
  
  class SolutionCopy(object):
      def rotate(self, nums, k):
          """
          :type nums: List[int]
          :type k: int
          :rtype: None Do not return anything, modify nums in-place instead.
          """
          # If k >= n, truncate k by n.
          n = len(nums)
          if k >= n:
              k -= n
  
          # Append right with left.
          nums[:] = nums[-k:] + nums[:-k]
  
  
  def main():
      # Ans: [5,6,7,1,2,3,4]
      nums = [1,2,3,4,5,6,7]
      k = 3
      SolutionCopy().rotate(nums, k)
      print nums
  
      # Ans: [3,99,-1,-100]
      nums = [-1,-100,3,99]
      k = 2
      SolutionCopy().rotate(nums, k)
      print nums
  
      # Ans: [2,1]
      nums = [1,2]
      k = 3
      SolutionCopy().rotate(nums, k)
      print nums
  
  
  if __name__ == '__main__':
      main()
  
subject: Complete copy sol