140 lines
3.6 KiB
Python
140 lines
3.6 KiB
Python
import fileinput
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import numpy
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DIRS = ["^", ">", "v", "<"]
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NORTH = 0
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EAST = 1
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SOUTH = 2
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WEST = 3
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TURN_LEFT = 0
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TURN_STRAIGHT = 1
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TURN_RIGHT = 2
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carts = 0
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cart_pos = []
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cart_dirs = []
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cart_turns = []
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def get_cart(x, y):
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try:
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pos = cart_pos.index((x, y))
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return pos
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except ValueError:
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raise IndexError
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def move_cart(cart, dx, dy):
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x, y = cart_pos[cart]
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cart_pos[cart] = (x + dx, y + dy)
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def remove_cart(cart):
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global carts
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carts -= 1
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cart_pos.pop(cart)
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cart_dirs.pop(cart)
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cart_turns.pop(cart)
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def add_cart(x, y, dir_, turn=TURN_LEFT):
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global carts
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carts += 1
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cart_pos.append((x, y))
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cart_dirs.append(dir_)
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cart_turns.append(turn)
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def print_field(field):
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for y, row in enumerate(field):
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for x, value in enumerate(row.decode("ascii")):
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try:
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cart = get_cart(x, y)
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print("\033[31;1;4m" + DIRS[cart_dirs[cart]], end="\033[0m")
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if value == '-':
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print("\u0335", end="")
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elif value == '|':
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print("\u20D2", end="")
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except IndexError:
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print(value, end="")
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print()
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print()
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for cart in range(carts):
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x, y = cart_pos[cart]
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dir_ = DIRS[cart_dirs[cart]]
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turn = cart_turns[cart]
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print(f"- ({x:>3d}, {y:>3d}) {dir_} {turn}")
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print()
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inp = []
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for y, line in enumerate(fileinput.input()):
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row = []
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for x, value in enumerate(line.rstrip("\n")):
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if value == "^": add_cart(x, y, NORTH); row.append("|")
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elif value == ">": add_cart(x, y, EAST); row.append("-")
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elif value == "v": add_cart(x, y, SOUTH); row.append("|")
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elif value == "<": add_cart(x, y, WEST); row.append("-")
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else:
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row.append(value)
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inp.append(row)
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field = numpy.chararray((len(inp), len(inp[0])))
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field[:] = inp
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one_more = False
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def step():
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# Move the carts
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order = sorted(range(carts), key=lambda cart: cart_pos[cart], reverse=True)
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while order:
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cart = order.pop()
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if cart_dirs[cart] == NORTH: move_cart(cart, 0, -1)
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elif cart_dirs[cart] == EAST: move_cart(cart, 1, 0)
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elif cart_dirs[cart] == SOUTH: move_cart(cart, 0, 1)
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elif cart_dirs[cart] == WEST: move_cart(cart, -1, 0)
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value = field[cart_pos[cart][::-1]]
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if value == b"+":
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cart_dirs[cart] += cart_turns[cart] - 1
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cart_dirs[cart] %= 4
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cart_turns[cart] = (cart_turns[cart] + 1) % 3
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elif value == b"/":
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if cart_dirs[cart] in (NORTH, SOUTH):
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cart_dirs[cart] = (cart_dirs[cart] + 1) % 4
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else:
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cart_dirs[cart] = (cart_dirs[cart] - 1) % 4
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elif value == b"\\":
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if cart_dirs[cart] in (EAST, WEST):
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cart_dirs[cart] = (cart_dirs[cart] + 1) % 4
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else:
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cart_dirs[cart] = (cart_dirs[cart] - 1) % 4
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elif value not in (b"-", b"|"):
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raise ValueError(value)
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u, c = numpy.unique(cart_pos, axis=0, return_counts=True)
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if len(u[c > 1]):
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for pos in u[c > 1]:
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print("crash at", pos)
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print(order)
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cart = get_cart(*pos)
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order = [x if x < cart else x - 1 for x in order if x != cart]
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remove_cart(cart)
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cart = get_cart(*pos)
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order = [x if x < cart else x - 1 for x in order if x != cart]
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remove_cart(cart)
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print(order)
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if carts == 1:
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print(cart_pos[0])
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return False
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return True
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print_field(field)
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while step():
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pass
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