61 lines
2.1 KiB
Python
61 lines
2.1 KiB
Python
# SPDX-License-Identifier: MIT
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# Copyright (c) 2021 Akumatic
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#
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# https://adventofcode.com/2021/day/25
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def parse_lines(lines: list) -> dict:
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x, y = len(lines[0]), len(lines)
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return {"x": x, "y": y, "grid": {(i, j): lines[j][i] for j in range(y) for i in range(x)}}
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def read_file(filename: str = "input.txt") -> list:
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with open(f"{__file__.rstrip('code.py')}{filename}", "r") as f:
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return parse_lines([line for line in f.read().strip().split("\n")])
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def move_herd(data: dict, herd: str) -> dict:
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new = {"x": data["x"], "y": data["y"], "grid": dict()}
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# take care of all moving cucumbers
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moving_positions = [pos for pos in data["grid"] if data["grid"][pos] == herd]
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for position in moving_positions:
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if can_move(data, position):
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new["grid"][get_next_position(data, position)] = data["grid"][position]
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new["grid"][position] = "."
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else: # position not in new["grid"]:
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new["grid"][position] = data["grid"][position]
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# take care of every other location
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for position in data["grid"]:
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if position not in new["grid"]:
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new["grid"][position] = data["grid"][position]
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return new
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def move_all(data: dict) -> dict:
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return move_herd(move_herd(data, ">"), "v")
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def get_next_position(data: dict, position: tuple) -> tuple:
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if data["grid"][position] == "v":
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return (position[0], (position[1] + 1) % data["y"])
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else: #data["grid"][position] == ">":
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return ((position[0] + 1) % data["x"], position[1])
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def can_move(data: dict, position: tuple) -> bool:
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if data["grid"][position] == ".":
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return False
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return data["grid"][get_next_position(data, position)] == "."
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def count_possible_steps(data: dict) -> int:
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return sum(int(can_move(data, pos)) for pos in data["grid"])
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def part1(data: dict) -> int:
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count = 1
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while count_possible_steps(data) > 0:
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data = move_all(data)
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count += 1
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return count
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def part2(data: dict) -> int:
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return 0 # not doable until all other 49 stars are done
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if __name__ == "__main__":
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vals = read_file()
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print(f"Part 1: {part1(vals)}")
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print(f"Part 2: {part2(vals)}")
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