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.

Hint:
Could you do it in-place with O(1) extra space?

思路

利用Python语言对于list操作的性质,可以得到空间复杂度为O(1)的结果。

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class Solution(object):
def rotate(self, nums, k):
"""
:type nums: List[int]
:type k: int
:rtype: void Do not return anything, modify nums in-place instead.
"""
length = len(nums)
if (k > length):
k = k % length
for i in range(length - k):
nums.append(nums[0])
del nums[0]