leet189. Rotate Array

题目：

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].

分析：

1. 将右侧元素旋转k次至左端
2. 当k=0时，数组无需旋转
3. 当k=n时，数组无需旋转
4. 当k>n时，相当于在3的基础上再旋转k-n次
5. 统一以上思路，对数组进行k=k%n次旋转操作
   

代码：

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.
        """
        if len(nums) > 1:
            k = k % len(nums)
            if k != 0:
                nums[:k - 1],nums[k:] = nums[- k:],nums[:-k]

思考：

1. 该代码在leetcode中优于88.9%的case