# -*- coding: utf-8 -*-

"""

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:

def rotate(self, nums, k):

"""

:type nums: List[int]

:type k: int

:rtype: void Do not return anything, modify nums in-place instead.

>>> s = Solution()

>>> test1, k1 = [-1,-100,3,99],2

>>> test2, k2 = [1],0

>>> test3, k3 = [1,2,3,4,5], 1

>>> test4, k4 = [1,2], 3

>>> s.rotate(test1, k1)

>>> print(test1)

[3, 99, -1, -100]

>>> s.rotate(test2, k2)

>>> print(test2)

[1]

>>> s.rotate(test3, k3)

>>> print(test3)

[5, 1, 2, 3, 4]

>>> s.rotate(test4, k4)

>>> print(test4)

[2, 1]

"""

if not k:

return

# 边界条件, k可能比数组长度还大

k = k % len(nums)

temp = nums[-k:]

nums[k:] = nums[0:-k]

nums[0:k] = temp

if __name__ == '__main__':

import doctest

doctest.testmod(verbose=True)