2023/day10.py

from collections import deque
import fileinput
from pprint import pprint
from dataclasses import dataclass

map = []

(sx, sy) = (0, 0)
for (j, line) in enumerate(fileinput.input()):
    map.append(list(line.strip()))
    if (x := line.find("S")) != -1:
        (sx, sy) = (x, j)

seen = set()
queue: deque[tuple[int, int, int]] = deque([(sx, sy, 0)])
distances = [[None] * len(map[0]) for _ in range(len(map))]

NS = "|"
WE = "-"
NE = "L"
NW = "J"
SW = "7"
SE = "F"

part1 = 0
while queue:
    (x, y, l) = queue.popleft()
    if (x, y) in seen:
        continue

    seen.add((x, y))
    distances[y][x] = l
    part1 = l

    match map[y][x]:
        case "S":
            if map[y - 1][x] in "|7F":
                queue.append((x, y - 1, l + 1))
            if map[y + 1][x] in "|LJ":
                queue.append((x, y + 1, l + 1))
            if map[y][x - 1] in "-LF":
                queue.append((x - 1, y, l + 1))
            if map[y][x + 1] in "-J7":
                queue.append((x + 1, y, l + 1))
        case "|":
            queue.append((x, y - 1, l + 1))
            queue.append((x, y + 1, l + 1))
        case "-":
            queue.append((x - 1, y, l + 1))
            queue.append((x + 1, y, l + 1))
        case "L":
            queue.append((x + 1, y, l + 1))
            queue.append((x, y - 1, l + 1))
        case "J":
            queue.append((x - 1, y, l + 1))
            queue.append((x, y - 1, l + 1))
        case "7":
            queue.append((x - 1, y, l + 1))
            queue.append((x, y + 1, l + 1))
        case "F":
            queue.append((x + 1, y, l + 1))
            queue.append((x, y + 1, l + 1))

part1 = 0
for l in distances:
    part1 = max(part1, 0, *[i for i in l if i])
print(part1)

side = set()
for y in range(len(map)):
    if map[y][0] == ".": side.add((0, y))
    if map[y][-1] == ".": side.add((len(map[0]) - 1, y))
for x in range(len(map[0])):
    if map[0][x] == ".": side.add((x, 0))
    if map[-1][x] == ".": side.add((x, len(map) - 1))

mapp = []
for (x, row) in enumerate(map):
    r = []
    for (y, c) in enumerate(row):
        match c:
            case ".":
                r.append(["..."]*3)
            case "S":
                r.append([".X.","XXX",".X."])
            case "-":
                r.append(["...","XXX","..."])
            case "|":
                r.append([".X.",".X.",".X."])
            case "7":
                r.append(["...","XX.",".X."])
            case "F":
                r.append(["...",".XX",".X."])
            case "J":
                r.append([".X.","XX.","..."])
            case "L":
                r.append([".X.",".XX","..."])
    mapp.append(r)

bigmap = []
for row in mapp:
    for y in range(3):
        r = []
        for col in row:
            for x in range(3):
                r.append(col[y][x])
        bigmap.append(r)
        print(r)

exterior = []
for y in range(len(bigmap)):
    if bigmap[y][0] == ".":
        exterior.append((0, y))
    if bigmap[y][-1] == ".":
        exterior.append((len(bigmap[0]) - 1, y))


for x in range(len(bigmap[0])):
    if bigmap[0][x] == ".":
        exterior.append((x, 0))
    if bigmap[-1][x] == ".":
        exterior.append((x, len(bigmap) - 1))

for (x, y) in exterior:
    if y < 0 or y > len(bigmap) - 1:
        continue
    if x < 0 or x > len(bigmap[y]) - 1:
        continue
    if bigmap[y][x] != ".":
        continue

    bigmap[y][x] = "O"

    exterior.append((x - 1, y))
    exterior.append((x + 1, y))
    exterior.append((x, y - 1))
    exterior.append((x, y + 1))

for row in distances:
    for c in row:
        print("X" if c is not None else ".", end="")
    print()

part2 = 0
for y in range(1, len(bigmap), 3):
    for x in range(1, len(bigmap[y]), 3):
        if bigmap[y][x] == "." or (distances[y // 3][x // 3] is None):
            part2 += 1
            map[y//3][x//3] = 'I'

print(part1, part2)