advent-of-code/2022/day22.py

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# -*- encoding: utf-8 -*-
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import re
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import sys
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import numpy as np
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VOID = 0
EMPTY = 1
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WALL = 2
TILE_FROM_CHAR = {" ": VOID, ".": EMPTY, "#": WALL}
board_map_s, direction_s = sys.stdin.read().split("\n\n")
# board
board_lines = board_map_s.splitlines()
max_line = max(len(line) for line in board_lines)
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board = np.array(
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[
[TILE_FROM_CHAR[c] for c in row] + [VOID] * (max_line - len(row))
for row in board_map_s.splitlines()
]
)
directions = [
int(p1) if p2 else p1 for p1, p2 in re.findall(R"(([0-9])+|L|R)", direction_s)
]
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invert = False
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y0 = 0
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x0 = np.where(board[0] == EMPTY)[0][0]
r0 = "E"
if invert:
board = board[::-1, ::-1]
y0 = board.shape[0] - 1
x0 = np.where(board[-1, :] == EMPTY)[0][-1]
r0 = "W"
# print(
# "\n".join(
# "".join(next(k for k, v in TILE_FROM_CHAR.items() if v == c) for c in row)
# for row in board
# )
# )
# find on each row and column the first and last non-void
row_first_non_void = np.argmax(board != VOID, axis=1)
row_last_non_void = board.shape[1] - np.argmax(board[:, ::-1] != VOID, axis=1) - 1
col_first_non_void = np.argmax(board != VOID, axis=0)
col_last_non_void = board.shape[0] - np.argmax(board[::-1, :] != VOID, axis=0) - 1
print(y0, x0, r0)
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for direction in directions:
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# print(f"{y0} {x0} {r0} ({direction})")
# r1 = {"N": "S", "S": "N", "W": "E", "E": "W"}[r0]
# print(f"{board.shape[0] - y0 - 1} {board.shape[1] - x0 - 1} {r1} ({direction})")
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if isinstance(direction, int):
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while direction > 0:
if r0 == "E":
xi = np.where(board[y0, x0 + 1 : x0 + direction + 1] == WALL)[0]
# if y0 == 12 and x0 == 81:
# print(
# xi,
# board[y0, x0 + 1 : x0 + direction],
# board[y0, x0 + direction],
# )
if len(xi):
# print("E1")
x0 = x0 + xi[0]
direction = 0
elif (
x0 + direction < board.shape[1]
and board[y0, x0 + direction] == EMPTY
):
# print("E2")
x0 = x0 + direction
direction = 0
elif board[y0, row_first_non_void[y0]] == WALL:
# print("E3")
x0 = row_last_non_void[y0]
direction = 0
else:
# print("E4")
direction = direction - (row_last_non_void[y0] - x0) - 1
x0 = row_first_non_void[y0]
elif r0 == "S":
yi = np.where(board[y0 + 1 : y0 + direction + 1, x0] == WALL)[0]
if len(yi):
# print("S1")
y0 = y0 + yi[0]
direction = 0
elif (
y0 + direction < board.shape[0]
and board[y0 + direction, x0] == EMPTY
):
# print("S2")
y0 = y0 + direction
direction = 0
elif board[col_first_non_void[x0], x0] == WALL:
print("S3")
y0 = col_last_non_void[x0]
direction = 0
else:
# print("S4")
direction = direction - (col_last_non_void[x0] - y0) - 1
y0 = col_first_non_void[x0]
elif r0 == "W":
left = max(x0 - direction - 1, 0)
xi = np.where(board[y0, left:x0] == WALL)[0]
if len(xi):
x0 = left + xi[-1] + 1
direction = 0
elif x0 - direction >= 0 and board[y0, x0 - direction] == EMPTY:
x0 = x0 - direction
direction = 0
elif board[y0, row_last_non_void[y0]] == WALL:
x0 = row_first_non_void[y0]
direction = 0
else:
# print("W", x0, row_first_non_void[y0], direction)
direction = direction - (x0 - row_first_non_void[y0]) - 1
x0 = row_last_non_void[y0]
elif r0 == "N":
top = max(y0 - direction - 1, 0)
yi = np.where(board[top:y0, x0] == WALL)[0]
if len(yi):
y0 = top + yi[-1] + 1
direction = 0
elif y0 - direction >= 0 and board[y0 - direction, x0] == EMPTY:
y0 = y0 - direction
direction = 0
elif board[col_last_non_void[x0], x0] == WALL:
y0 = col_first_non_void[x0]
direction = 0
else:
direction = direction - (y0 - col_first_non_void[x0]) - 1
y0 = col_last_non_void[x0]
else:
r0 = {
"E": {"L": "N", "R": "S"},
"N": {"L": "W", "R": "E"},
"W": {"L": "S", "R": "N"},
"S": {"L": "E", "R": "W"},
}[r0][direction]
if invert:
print(y0, x0, r0, "->", end=" ")
x0, y0, r0 = (
board.shape[1] - x0 - 1,
board.shape[0] - y0 - 1,
{"N": "S", "S": "N", "W": "E", "E": "W"}[r0],
)
print(y0, x0, r0)
score = {"E": 0, "S": 1, "W": 2, "N": 3}
answer_1 = 1000 * (1 + y0) + 4 * (1 + x0) + score[r0]
print(f"answer 1 is {answer_1}")