Maximum Unsorted Subarray

Given an array A of non-negative integers of size N. Find the minimum sub-array A_l, A_l+1 ,..., A_r such that if we sort(in ascending order) that sub-array, then the whole array should get sorted. If A is already sorted, output -1.

1 <= N <= 1000000
1 <= A[i] <= 1000000

First and only argument is an array of non-negative integers of size N.

Return an array of length two where the first element denotes the starting index(0-based) and the second element denotes the ending index(0-based) of the sub-array. If the array is already sorted, return an array containing only one element i.e. -1.

Input 1:

A = [1, 3, 2, 4, 5]

Input 2:

A = [1, 2, 3, 4, 5]

Output 1:

[1, 2]

Output 2:

[-1]

Explanation 1:

If we sort the sub-array A1, A2, then the whole array A gets sorted.

Explanation 2:

A is already sorted.