def neighbors(x: int, y: int) -> Set[Coord]: retVal = [] if x > 0: retVal.append(Coord(x-1, y)) if x < 127: retVal.append(Coord(x+1, y)) if y > 0: retVal.append(Coord(x, y-1)) if y < 127: retVal.append(Coord(x, y+1)) return retVal
def part1(inp: Set[Coord], cycles: int, size: int, p2 = False) -> int:
while cycles > 0:
current = inp.copy()
next_set = set()
for point in current:
c = 0
for n in point.full_neighbors():
c2 = 0
if n in current:
c += 1
elif 0 <= n.x < size and 0 <= n.y < size:
c2 = [p for p in n.full_neighbors() if p in current]
if len(c2) == 3:
next_set.add(n)
if c in [2, 3]:
next_set.add(point)
cycles -= 1
inp = next_set.copy()
if p2:
inp.update({Coord(0, 0), Coord(0, 99), Coord(99, 99), Coord(99, 0)})
return len(inp)
def part1(inp: List[str]) -> str:
retVal = ''
retVal2 = 1
loc = Coord(inp[0].index("|"), 0)
max_y = len(inp)
max_x = len(inp[0])
direction = "s"
directions = {
"n": Coord(0, -1),
"s": Coord(0, 1),
"w": Coord(-1, 0),
"e": Coord(1, 0)
}
opposites = {"n": "s", "s": "n", "w": "e", "e": "w"}
loc = loc + directions[direction]
uppers = list(string.ascii_uppercase)
while max_x > loc.x >= 0 and max_y > loc.y >= 0:
spot = inp[loc.y][loc.x]
# print(loc)
if spot == "+":
# find which direction is next
for k, v in directions.items():
if k != direction and k != opposites[direction]:
n = inp[loc.y + v.y][loc.x + v.x]
else:
n = ''
if n in ["|", "-"]:
direction = k
break
# print(f"New direction: {direction}")
elif spot == " ":
# assert 0 == 1, f"We've strayed off the trail! {retVal}"
return retVal, retVal2
elif spot in uppers:
retVal += spot
elif spot == 'E':
print(spot)
loc = loc + directions[direction]
retVal2 += 1
return retVal, retVal2
def part2(inp: str) -> int:
def neighbors(x: int, y: int) -> Set[Coord]:
retVal = []
if x > 0:
retVal.append(Coord(x-1, y))
if x < 127:
retVal.append(Coord(x+1, y))
if y > 0:
retVal.append(Coord(x, y-1))
if y < 127:
retVal.append(Coord(x, y+1))
return retVal
grid = part1(inp)
grouped = []
groups = 0
x = y = 0
while x < 128:
while y < 128:
if grid[y][x] == "1":
point = Coord(x, y)
else:
y += 1
continue
if point not in grouped:
groups += 1
else:
y += 1
continue
edges = [point]
group = [point]
while True:
new_edges = []
for p in group:
try:
new_edges.extend([z for z in neighbors(p.x, p.y) if grid[z.y][z.x] == "1" and z not in group and z not in new_edges])
except IndexError:
print(new_edges)
return
if not new_edges:
break
edges = new_edges.copy()
group.extend(edges)
grouped.extend(group)
y += 1
x += 1
y = 0
assert sum(x.count('1') for x in grid) == len(grouped), "Not all items were grouped"
return groups
def part2(inp: List[str]) -> int:
on = {Coord(x, y): 0 for x in range(1000) for y in range(1000)}
for line in inp:
if line.count(" ") == 3:
command, start, th, end = line.split()
else:
commanda, commandb, start, th, end = line.split()
command = commanda + commandb
start = [int(x) for x in start.split(',')]
end = [int(x) for x in end.split(',')]
if command == "toggle":
for c in light_section(start, end):
on[c] += 2
elif command == "turnoff":
for c in light_section(start, end):
if on[c] > 0:
on[c] -= 1
else:
for c in light_section(start, end):
on[c] += 1
return sum(x for x in on.values())
if c in [2, 3]:
next_set.add(point)
cycles -= 1
inp = next_set.copy()
if p2:
inp.update({Coord(0, 0), Coord(0, 99), Coord(99, 99), Coord(99, 0)})
return len(inp)
TEST_DATA = """.#.#.#
...##.
#....#
..#...
#.#..#
####.."""
if __name__ == "__main__":
import os, timeit
FILE_DIR = os.path.dirname(os.path.abspath(__file__))
with open(os.path.join(FILE_DIR, "day18.input")) as f:
DATA = f.read().strip()
DATA = DATA.split("\n")
LIGHTS = {Coord(x, y) for y in range(len(DATA)) for x in range(len(DATA)) if DATA[x][y] == "#"}
print(f"Part one: {part1(LIGHTS, 100, len(DATA))}") # not 9996, too high;
LIGHTS = {Coord(x, y) for y in range(len(DATA)) for x in range(len(DATA)) if DATA[x][y] == "#"}
LIGHTS.update({Coord(0, 0), Coord(0, 99), Coord(99, 99), Coord(99, 0)})
print(f"Part two: {part1(LIGHTS, 100, len(DATA), True)}")
# print(f"Time: {timeit.timeit('', setup='from __main__ import ', number = 1)}")
def light_section(start: List[int], end: List[int]) -> Set[Coord]:
for x in range(start[0], end[0] + 1):
for y in range(start[1], end[1] + 1):
yield Coord(x, y)