题目
Given an array, rotate the array to the right by k steps, where k is non-negative.
Follow up:
- 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?
解题思路
对数组进行翻转，之后对前k个和后n-k个数分别进行翻转
代码
class Solution:
def rotate(self, nums: List[int], k: int) -> None:
"""
Do not return anything, modify nums in-place instead.
"""
def rev(nums, l, r):
while l < r:
nums[l], nums[r] = nums[r], nums[l]
l += 1
r -= 1
n = len(nums)
k %= n
rev(nums, 0, n - 1)
rev(nums, 0, k - 1)
rev(nums, k, n - 1)
