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#!/usr/bin/env python3
import aoc20
import sys
import functools
def vis(board):
s = ""
for r in board:
for c in r:
s += "T" if c[0] else "F"
s += str(c[1]) if c[1] >= 0 else "-"
s += str(c[2])
s += " "
s += "\n"
return s
def read(lines):
board = []
h = len(lines)
w = len(lines[0]) - 1
for y in range(h):
row = []
for x in range(w):
if lines[y][x] == "L":
row.append([False, 0, 0, []])
elif lines[y][x] == ".":
row.append([False, -1, 0, []])
board.append(row)
def update_in_sight(x, y):
for dy in range(-1, 1+1):
for dx in range(-1, 1+1):
if dy == dx == 0:
continue
step = 0
while True:
step += 1
px, py = x + (dx * step), y + (dy * step)
if px < 0 or px >= w or py < 0 or py >= h:
break
if board[py][px][1] != -1:
board[py][px][3].append((x, y))
break
for y in range(h):
for x in range(w):
update_in_sight(x, y)
return board, w, h
@functools.cache
def neighbours_occ(p, w, h):
n = []
for dy in range(-1, 1+1):
py = p[1] + dy
if 0 <= py < h:
for dx in range(-1, 1+1):
if dy == dx == 0:
continue
px = p[0] + dx
if 0 <= px < w:
n.append((px, py))
return n
def pt1(_in):
board, w, h = read(_in)
while True:
changed = False
for y in range(h):
for x in range(w):
if not board[y][x][0] and board[y][x][1] == 0:
changed = True
board[y][x][0] = True
for nx, ny in neighbours_occ((x, y), w, h):
board[ny][nx][2] += 1
if board[y][x][0] and board[y][x][1] >= 4:
changed = True
board[y][x][0] = False
for nx, ny in neighbours_occ((x, y), w, h):
board[ny][nx][2] -= 1
for y in range(h):
for x in range(w):
if board[y][x][1] != -1:
board[y][x][1] = board[y][x][2]
if not changed:
break
res = 0
for y in range(h):
for x in range(w):
if board[y][x][0]:
res += 1
return res
def pt2(_in):
board, w, h = read(_in)
while True:
changed = False
for y in range(h):
for x in range(w):
if not board[y][x][0] and board[y][x][1] == 0:
changed = True
board[y][x][0] = True
for nx, ny in board[y][x][3]:
board[ny][nx][2] += 1
if board[y][x][0] and board[y][x][1] >= 5:
changed = True
board[y][x][0] = False
for nx, ny in board[y][x][3]:
board[ny][nx][2] -= 1
for y in range(h):
for x in range(w):
if board[y][x][1] != -1:
board[y][x][1] = board[y][x][2]
if not changed:
break
res = 0
for y in range(h):
for x in range(w):
if board[y][x][0]:
res += 1
return res
if __name__ == "__main__":
input = aoc20.read_input(sys.argv[1:], 11)
print(pt1(input))
print(pt2(input))
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