first

window_sliding_product.py

large_number = open("source.txt", 'r').read()
large_number_array = list(map(int, str(large_number)))


def find_max_product(k):
    max_product = 1
    for i in range(0, k):
        max_product *= large_number_array[i]

    window_product = max_product
    for i in range(k, len(large_number_array)):
        window_product = window_product // large_number_array[i - k] * large_number_array[i]
        max_product = max(window_product, max_product)
    return max_product


assert find_max_product(4) == 5832
print(find_max_product(13))