Problem Statement

Given an array, find the length of the smallest subarray in it which when sorted will sort the whole array.

Example 1:

Input: [1, 2, 5, 3, 7, 10, 9, 12]
Output: 5
Explanation: We need to sort only the subarray [5, 3, 7, 10, 9] to make the whole array sorted

Example 2:

Input: [1, 3, 2, 0, -1, 7, 10]
Output: 5
Explanation: We need to sort only the subarray [1, 3, 2, 0, -1] to make the whole array sorted

Example 3:

Input: [1, 2, 3]
Output: 0
Explanation: The array is already sorted

Example 4:

Input: [3, 2, 1]
Output: 3
Explanation: The whole array needs to be sorted.

Constraints:

• 1 <= arr.length <= 10⁴
• -10⁵ <= arr[i] <= 10⁵

Try it yourself

Try solving this question here: