36 lines
1.1 KiB
Python
36 lines
1.1 KiB
Python
|
# SPDX-License-Identifier: MIT
|
||
|
|
# Copyright (c) 2020 Akumatic
|
||
|
|
#
|
||
|
|
#https://adventofcode.com/2020/day/13
|
||
|
|
|
||
|
|
def readFile() -> tuple:
|
||
|
|
with open(f"{__file__.rstrip('code.py')}input.txt", "r") as f:
|
||
|
|
timestamp = int(f.readline().strip())
|
||
|
|
values = f.readline().strip().split(",")
|
||
|
|
bus_ids = [{"value": int(values[i]), "index": i}
|
||
|
|
for i in range(len(values))
|
||
|
|
if values[i] != "x"]
|
||
|
|
return timestamp, bus_ids
|
||
|
|
|
||
|
|
def part1(timestamp: int, bus_ids: list) -> int:
|
||
|
|
min = timestamp
|
||
|
|
min_id = None
|
||
|
|
for bus in bus_ids:
|
||
|
|
waiting_time = bus["value"] - (timestamp % bus["value"])
|
||
|
|
if waiting_time < min:
|
||
|
|
min = waiting_time
|
||
|
|
min_id = bus["value"]
|
||
|
|
return min * min_id
|
||
|
|
|
||
|
|
def part2(bus_ids: list) -> int:
|
||
|
|
time, step = 1, 1
|
||
|
|
for bus in bus_ids:
|
||
|
|
while (time + bus["index"]) % bus["value"] != 0:
|
||
|
|
time += step
|
||
|
|
step *= bus["value"]
|
||
|
|
return time
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
input = readFile()
|
||
|
|
print(f"Part 1: {part1(*input)}")
|
||
|
|
print(f"Part 2: {part2(input[1])}")
|