Hello community,

I was trying to solve this problem. I could not come up with a solution for the same.

Given an array A of N elements, you have top tell the minimum number of operations to sort the array. An operation is defined as follows:
1. Take two indexes [l, r] in the array.
2. Reverse the array elements (A[l], A[l+1], ..., A[r]).
E.g. : A = [3, 2, 1, 4]
Ans = 1.
Explanation: l = 0, r= 2. Flip [3, 2, 1] ==> A = [1,2,3,4]

Note:

I was trying to solve the easier version of the problem where I can only take a number K (<=N) and reverse the first K elements. This is known as Pancake sorting. I was trying to find the optimal number of reversals in pancake sorting.