Max double slice sum

Question

Recently, I tried to solve the Max Double Slice Sum problem in codility which is a variant of max slice problem. My Solution was to look for a slice that has maximum value w

Answer 1

C# solution 100/100

public int solution(int[] A) {
        int[] forw = new int[A.Length];
        int[] rewi = new int[A.Length];

        bool isAllNeg = true;
        for (int i = 1; i < A.Length; i++)
        {
            forw[i] = Math.Max(0, forw[i - 1] + A[i]);
            if (A[i] > 0 && isAllNeg) isAllNeg = false;

        }

        if (isAllNeg)
            return 0;

        for (int i = A.Length - 2; i >= 0; i--)
        {
            rewi[i] = Math.Max(0, rewi[i + 1] + A[i]);
        }

        int maxsum = 0;
        for (int i = 1; i < A.Length - 1; i++)
        {
            maxsum = Math.Max(maxsum, forw[i - 1] + rewi[i + 1]);
        }

        return maxsum;
}