Maximum Subarray

Problem:

Find the contiguous subarray within an array (containing at least one number) which has the largest sum.

For example, given the array [−2,1,−3,4,−1,2,1,−5,4],
the contiguous subarray [4,−1,2,1] has the largest sum = 6.

Solution:

class Solution {
public:
    int maxSubArray(int A[], int n) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        if (n < 1)
            return 0;
       
        int max_sum = A[0];
        int sum_so_far = 0;
        for (int i = 0; i < n; i++) {
            sum_so_far += A[i];
            max_sum = max(max_sum, sum_so_far);
            if (sum_so_far < 0)
                sum_so_far = 0;
        }
        return max_sum;
    }
};