LeetCode in Kotlin

581. Shortest Unsorted Continuous Subarray

Medium

Given an integer array nums, you need to find one continuous subarray that if you only sort this subarray in ascending order, then the whole array will be sorted in ascending order.

Return the shortest such subarray and output its length.

Example 1:

Input: nums = [2,6,4,8,10,9,15]

Output: 5

Explanation: You need to sort [6, 4, 8, 10, 9] in ascending order to make the whole array sorted in ascending order.

Example 2:

Input: nums = [1,2,3,4]

Output: 0

Example 3:

Input: nums = [1]

Output: 0

Constraints:

Follow up: Can you solve it in O(n) time complexity?

Solution

class Solution {
    fun findUnsortedSubarray(nums: IntArray): Int {
        var end = -2
        var max = Int.MIN_VALUE
        for (i in nums.indices) {
            max = Math.max(max, nums[i])
            if (nums[i] < max) {
                end = i
            }
        }
        var start = -1
        var min = Int.MAX_VALUE
        for (i in nums.indices.reversed()) {
            min = Math.min(min, nums[i])
            if (nums[i] > min) {
                start = i
            }
        }
        return end - start + 1
    }
}