AoC day 09

09.py

from itertools import combinations


def validate_xmas(validate_list: list, preamble_len: int = 5) -> int:
    """
    takes list, returns the first item that doesn't fit, otherwise returns -1 for a valid list
    :param validate_list:
    :param preamble_len:
    :return:
    """
    for i in range(preamble_len, len(validate_list)):
        if validate_list[i] not in [x + y for x, y in combinations(validate_list[i - preamble_len:i], 2)]:
            return i
    return -1


raw = '''35
20
15
25
47
40
62
55
65
95
102
117
150
182
127
219
299
277
309
576'''

with open('09.input.txt') as f:
    raw = f.read()

xmas_list = raw.split('\n')
xmas_list = [int(i) for i in xmas_list]
item_number = validate_xmas(xmas_list, preamble_len=25)
print(item_number, xmas_list[item_number])  # 3199139634

for a in range(2, len(xmas_list)):
    for b in range(len(xmas_list) - a):
        if sum(xmas_list[b:a + b]) == xmas_list[item_number]:
            big = max(xmas_list[b:a + b])
            small = min(xmas_list[b:a + b])
            print(a, b, big + small)