Program to find Maximum sum of a subset in an array

I came up with the efficient O(n) solution for this problem. If you have better solution to this problem; Please post your solution as comment. Also remember that, the largest sum could also be among all negative numbers as well, the sum is not necessarily a positive sum.

int MaxSumSubArray(int *a, int len, int *start, int *end)
{
    int max = INT_MIN;
    int min = 0;
    int sum = 0;
    *start = -1;
    *end = -1;

    for (int i = 0, j = 0; i < len; i++)
    {
        sum += a[i];
        if (sum > max)
        {
            *start = j;
            *end = i;
            max = sum;
        }

        if (sum < 0)
        {
            j = i + 1;
            sum = 0;
        }
    }
    return max;
}

we can call this api as follows:

int a[]={-3, -2, -10, -4, -7, -8, -10, -10, -100, -12, -3};
int s1 = 0;
int s2 = 0;
int sum = MaxSumSubArray(a, sizeof(a)/sizeof(int), &s1, &s2);