def max_subarray_sum(lst):
max_sum = 0;
max_till_i = 0;
len_lst = len(lst)
for i in range(len_lst):
max_till_i = max_till_i + lst[i]
max_till_i = max(max_till_i, 0)
max_sum = max(max_sum, max_till_i)
return max_sum
lst = [1, -2, 2, -3, 4, -1, -1, 2, 3, -5, 4]
print(max_subarray_sum(lst))
'''
run:
7
'''