mirror of
https://github.com/Crocmagnon/advent-of-code.git
synced 2024-05-04 10:55:10 +02:00
69 lines
1.9 KiB
Python
69 lines
1.9 KiB
Python
from typing import Union
|
|
|
|
|
|
def main(filename: str, expected_part_1: int = None, expected_part_2: int = None):
|
|
print(f"\n+ Running on {filename}")
|
|
with open(filename) as f:
|
|
starting_numbers = list(map(int, f.read().strip().split("\n")[0].split(",")))
|
|
|
|
counter_part_1 = solve_part_1(starting_numbers)
|
|
|
|
print(f"1. Found {counter_part_1}")
|
|
if expected_part_1:
|
|
assert expected_part_1 == counter_part_1
|
|
|
|
counter_part_2 = solve_part_2(starting_numbers)
|
|
print(f"2. Found {counter_part_2}")
|
|
if expected_part_2:
|
|
assert expected_part_2 == counter_part_2
|
|
|
|
|
|
SeenTuple = Union[tuple[int], tuple[int, int]]
|
|
Seen = dict[int, SeenTuple]
|
|
|
|
|
|
def solve_part_1(starting_numbers):
|
|
return solve(starting_numbers, 2020)
|
|
|
|
|
|
def solve(starting_numbers, limit):
|
|
seen = dict() # type: Seen
|
|
previous = 0
|
|
for turn, current in enumerate(starting_numbers):
|
|
seen[current] = (turn,)
|
|
previous = current
|
|
previous_first_time = True
|
|
for turn in range(len(starting_numbers), limit):
|
|
if previous_first_time:
|
|
current = 0
|
|
else:
|
|
current = seen[previous][0] - seen[previous][1]
|
|
seen[current] = seen_tuple(seen, current, turn)
|
|
previous = current
|
|
previous_first_time = first_time_seen(seen, previous)
|
|
return previous
|
|
|
|
|
|
def first_time_seen(seen: Seen, previous: int) -> bool:
|
|
return len(seen[previous]) == 1
|
|
|
|
|
|
def seen_tuple(seen: Seen, current: int, turn: int) -> SeenTuple:
|
|
try:
|
|
existing = seen[current]
|
|
return turn, existing[0]
|
|
except KeyError:
|
|
return (turn,)
|
|
|
|
|
|
def solve_part_2(starting_numbers):
|
|
return solve(starting_numbers, 30_000_000)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main("inputs/day15-test1", 436, 175594)
|
|
main("inputs/day15-test2", 1, 2578)
|
|
main("inputs/day15-test6", 438, 18)
|
|
main("inputs/day15-test7", 1836, 362)
|
|
main("inputs/day15", 595, 1708310)
|