Given a log of stock prices compute the maximum possible earning.

max_profit_diff_stock.py

def solution(A):
    # write your code in Python 3.6
    max_diff = float('-inf')
    cur_sum = 0
    n = len(A)
    for idx, num in zip(range(1, n), A[1:]):
        diff = num - A[idx-1]
        if cur_sum > 0:
            cur_sum += diff
        else:
            cur_sum = diff
        # print('diff, cur_sum', diff, cur_sum)
        max_diff = max(max_diff, cur_sum)
    return max(max_diff, 0)