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AdventOfCode/2020/solutions/day_24.py
2020-12-25 23:50:29 +01:00

145 lines
3.9 KiB
Python

"""AOC 2020 Day 24"""
import pathlib
import time
import re
import itertools
TEST_INPUT = """sesenwnenenewseeswwswswwnenewsewsw
neeenesenwnwwswnenewnwwsewnenwseswesw
seswneswswsenwwnwse
nwnwneseeswswnenewneswwnewseswneseene
swweswneswnenwsewnwneneseenw
eesenwseswswnenwswnwnwsewwnwsene
sewnenenenesenwsewnenwwwse
wenwwweseeeweswwwnwwe
wsweesenenewnwwnwsenewsenwwsesesenwne
neeswseenwwswnwswswnw
nenwswwsewswnenenewsenwsenwnesesenew
enewnwewneswsewnwswenweswnenwsenwsw
sweneswneswneneenwnewenewwneswswnese
swwesenesewenwneswnwwneseswwne
enesenwswwswneneswsenwnewswseenwsese
wnwnesenesenenwwnenwsewesewsesesew
nenewswnwewswnenesenwnesewesw
eneswnwswnwsenenwnwnwwseeswneewsenese
neswnwewnwnwseenwseesewsenwsweewe
wseweeenwnesenwwwswnew"""
STEPMAP = {
'e': (1, 0),
'se': (1, 1),
'sw': (0, 1),
'w': (-1, 0),
'nw': (-1, -1),
'ne': (0, -1)
}
def read_input(input_path: str) -> str:
"""take input file path and return a str with the file's content"""
with open(input_path, 'r') as input_file:
input_data = input_file.read().strip()
return input_data
def extract(input_data: str) -> set:
"""take input data and return the appropriate data structure"""
rexp_steps = re.compile(r'e|se|sw|w|nw|ne')
tiles_steps = [rexp_steps.findall(line) for line in input_data.split('\n')]
black_tiles = set()
for steps in tiles_steps:
dst_tile = find_dst_tile(steps)
if dst_tile in black_tiles:
black_tiles.remove(dst_tile)
else:
black_tiles.add(dst_tile)
return black_tiles
def find_dst_tile(steps: list) -> tuple:
"""calculate the destination tile based on the steps"""
x_dst, y_dst = 0, 0
for step in steps:
d_x, d_y = STEPMAP[step]
x_dst += d_x
y_dst += d_y
return x_dst, y_dst
def count_black_neighbors(tiles: set, x_tile: int, y_tile: int) -> int:
"""return the number of black adjacent tile of a given one"""
black_neighbors = 0
for d_x, d_y in STEPMAP.values():
if (x_tile+d_x, y_tile+d_y) in tiles:
black_neighbors += 1
return black_neighbors
def calculate_floor_bounds(tiles: set) -> tuple:
"""return the floor boundaries"""
min_x = float('Inf')
max_x = float('-Inf')
min_y = float('Inf')
max_y = float('-Inf')
for x_tile, y_tile in tiles:
if x_tile < min_x:
min_x = x_tile
elif x_tile > max_x:
max_x = x_tile
if y_tile < min_y:
min_y = y_tile
elif y_tile > max_y:
max_y = y_tile
return range(min_x-1, max_x+2), range(min_y-1, max_y+2)
def flip_tiles(tiles: set) -> set:
"""calculate the new daily floor"""
new_floor = set()
for tile in itertools.product(*calculate_floor_bounds(tiles)):
black_neighbors = count_black_neighbors(tiles, *tile)
if tile in tiles and not (black_neighbors == 0 or black_neighbors > 2):
new_floor.add(tile)
elif tile not in tiles and black_neighbors == 2:
new_floor.add(tile)
return new_floor
def part1(entries: set) -> int:
"""part1 solver"""
return len(entries)
def part2(entries: list) -> int:
"""part2 solver"""
for _ in range(100):
entries = flip_tiles(entries)
return len(entries)
def test_input_day_24():
"""pytest testing function"""
entries = extract(TEST_INPUT)
assert part1(entries) == 10
assert part2(entries) == 2208
def test_bench_day_24(benchmark):
"""pytest-benchmark function"""
benchmark(main)
def main():
"""main function"""
input_path = str(pathlib.Path(__file__).resolve().parent.parent) + "/inputs/" + str(pathlib.Path(__file__).stem)
start_time = time.time()
input_data = read_input(input_path)
entries = extract(input_data)
print("Part 1: %s" % part1(entries))
print("Part 2: %s" % part2(entries))
end_time = time.time()
print("Execution time: %f" % (end_time-start_time))
if __name__ == "__main__":
main()