day09.py

import itertools

def part1(numbers):
    size = 25
    for i in range(len(numbers)):
        found = False
        for x, y in itertools.combinations(numbers[i:i+size], 2):
            if x + y == numbers[i+size]:
                found = True
        if not found:
            return numbers[i+size]

def part2(numbers, invalid_number):
    for i, n in enumerate(numbers):
        sum = n
        for j in range(i+1, len(numbers)):
            sum += numbers[j]
            seq = numbers[i:j+1]
            if sum == invalid_number:
                return min(seq) + max(seq)
            elif sum > invalid_number:
                break

def main(inp):
    with open(inp) as f:
        lines = f.read().splitlines()
    numbers = list(map(int, lines))
    invalid_number = part1(numbers)
    res2 = part2(numbers, invalid_number)
    return invalid_number, res2

if __name__ == '__main__':
    a, b = main('../input/input09.txt')
    print('day09.1:', a)
    print('day09.2:', b)