[LeetCode]#1752. Check if Array Is Sorted and Rotated

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:

  1. Sort nums as c_n.
  2. nums+nums
  3. get c_n[1:-1]
  4. 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

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