LeetCode in Kotlin

1752. Check if Array Is Sorted and Rotated

Easy

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.

Example 3:

Input: nums = [1,2,3]

Output: true

Explanation: [1,2,3] is the original sorted array. You can rotate the array by x = 0 positions (i.e. no rotation) to make nums.

Constraints:

Solution

class Solution {
    fun check(nums: IntArray): Boolean {
        var checker = 0
        for (i in 1 until nums.size) {
            if (nums[i - 1] > nums[i]) {
                checker++
            }
        }
        // checking if the last element is greater than the first
        if (nums[nums.size - 1] > nums[0]) {
            checker++
        }
        return checker <= 1
    }
}