This problem is from a hiring challenge so please don’t ask for link.

We have **N** numbers, we have to find the maximum sum of these number by flipping **at least** one or more numbers consecutively. We can apply flipping only once.

Flipping change the sign of the number (means if a number in less than zero it become greater than zero with same value and vice versa)

-2 **after flipping** become 2

5 **after flipping** becomes -5

My approach : Find the subarray with minimum sum(msum). Take sum all elements then

ans = sum - 2 * msum

What’s wrong with this approach as I got only partial marks ?

Constraints :

1 <= N <= 500

-1000 <= A[i] <= 1000