towards_max_contiguous_sum

def helper(a):
    if len(a) == 0
    # base case
return 0, 0
  else:
      # recursive case
      best_prefix_total, best_span_total = helper(a[1:])
      # TODO
      return foo, bar
    
# after getting this recursion working, then we would need to add memoization

def solve(a):
    best_prefix_total, best_span_total = helper(a)
    return best_span_total

def brute_force(a):
    return max([sum(a[i:j]) for i in range(len(a)) for j in range(len(a)) if j - i >= 0])

@given(st.lists(st.integers()))
def test_against_brute_force(self, a):
    self.assertEqual(solve(a), brute_force(a))