Largest sum contiguous subarray (Interview Question) [duplicate]

Answer 1

You can use Kadane's algorithm which runs in O(n).

Here is the algorithm (shamelessly copied from here)

Initialize:
    max_so_far = 0
    max_ending_here = 0

Loop for each element of the array
  (a) max_ending_here = max_ending_here + a[i]
  (b) if(max_ending_here < 0)
            max_ending_here = 0
  (c) if(max_so_far < max_ending_here)
            max_so_far = max_ending_here
return max_so_far