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from collections import deque
input = "data/15_2024.txt"
data = open(input).read().strip()
lines, instrs = data.split("\n\n")
lines = lines.split("\n")
def solve(lines, part2):
rows = len(lines)
cols = len(lines[0])
lines = [[lines[r][c] for c in range(cols)] for r in range(rows)]
if part2:
big = []
for r in range(rows):
row = []
for c in range(cols):
if lines[r][c] == "#":
row.append("#")
row.append("#")
if lines[r][c] == "O":
row.append("[")
row.append("]")
if lines[r][c] == ".":
row.append(".")
row.append(".")
if lines[r][c] == "@":
row.append("@")
row.append(".")
big.append(row)
lines = big
cols *= 2
for r in range(rows):
for c in range(cols):
if lines[r][c] == "@":
sr, sc = r, c
lines[r][c] = "."
r, c = sr, sc
for inst in instrs:
if inst == "\n":
continue
dr, dc = {"^": (-1, 0), ">": (0, 1), "v": (1, 0), "<": (0, -1)}[inst]
rr, cc = r + dr, c + dc
if lines[rr][cc] == "#":
continue
elif lines[rr][cc] == ".":
r, c = rr, cc
elif lines[rr][cc] in ["[", "]", "O"]:
q = deque([(r, c)])
vis = set()
ok = True
while q:
rr, cc = q.popleft()
if (rr, cc) in vis:
continue
vis.add((rr, cc))
rrr, ccc = rr + dr, cc + dc
if lines[rrr][ccc] == "#":
ok = False
break
if lines[rrr][ccc] == "O":
q.append((rrr, ccc))
if lines[rrr][ccc] == "[":
q.append((rrr, ccc))
assert lines[rrr][ccc + 1] == "]"
q.append((rrr, ccc + 1))
if lines[rrr][ccc] == "]":
q.append((rrr, ccc))
assert lines[rrr][ccc - 1] == "["
q.append((rrr, ccc - 1))
if not ok:
continue
while len(vis) > 0:
for rr, cc in sorted(vis):
rrr, ccc = rr + dr, cc + dc
if (rrr, ccc) not in vis:
assert lines[rrr][ccc] == "."
lines[rrr][ccc] = lines[rr][cc]
lines[rr][cc] = "."
vis.remove((rr, cc))
r = r + dr
c = c + dc
res = 0
for r in range(rows):
for c in range(cols):
if lines[r][c] in ["[", "O"]:
res += 100 * r + c
return res
print(solve(lines, False))
print(solve(lines, True))
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