[LeetCode]#1752. Check if Array Is Sorted and Rotated
2 min readFeb 18, 2021
Environment: Python 3.8
Key technique: sorted
Given an array nums
, return true
if the array was originally sorted in non-decreasing order, then rotated some number of positions (including zero). Otherwise, return false
.
There may be duplicates in the original array.
Note: An array A
rotated by x
positions results in an array B
of the same length such that A[i] == B[(i+x) % A.length]
, where %
is the modulo operation.
Example 1:
Input: nums = [3,4,5,1,2]
Output: true
Explanation: [1,2,3,4,5] is the original sorted array.
You can rotate the array by x = 3 positions to begin on the the element of value 3: [3,4,5,1,2].
Example 2:
Input: nums = [2,1,3,4]
Output: false
Explanation: There is no sorted array once rotated that can make nums.
Analysis:
- Sort nums as c_n.
- nums+nums
- get c_n[1:-1]
- Check c_n is in nums
Solution:
class Solution(object):
def check(self, nums):
c_n=sorted(nums)
nums+=nums
if str(c_n)[1:-1] in str(nums):
return True
Submissions:
Reference:
https://leetcode.com/problems/check-if-array-is-sorted-and-rotated/discuss/1064690/Python-simple