aoc-2020-python-day9.py

from itertools import combinations


def get_input():
    with open('./input9.txt') as inp:
        return inp.read().strip().split('\n')


def part1():
    inp = get_input()
    pre = 25
    n = 2
    c = 25
    d = []

    for cursor, _ in enumerate(inp, start=c):
        if not any(sum(x) == int(inp[cursor]) for x in combinations(map(int, inp[cursor-pre:cursor]), n)):
            return int(inp[cursor])


def part2(p1):
    inp = list(map(int, get_input()))
    n = len(inp)
    results = next(x for x in (next(inp[i:j] for j in range(i + 1, n) if sum(inp[i:j]) >= p1) for i in range(n)) if sum(x) == p1)
    return sum([min(results), max(results)])


if __name__ == "__main__":
    p1 = part1()
    print(p1)
    print(part2(p1))