diff --git a/src/day12.py b/src/day12.py new file mode 100644 index 0000000..5b97072 --- /dev/null +++ b/src/day12.py @@ -0,0 +1,80 @@ +import collections +import string +from dataclasses import dataclass +from typing import Union + +from cpl_core.console import Console +from cpl_query.extension import List + +from aoc.aoc import get_input + +# global vars +day = 12 +aoc_input = get_input(2022, day) +aoc_input1 = """Sabqponm +abcryxxl +accszExk +acctuvwj +abdefghi""" + + +@dataclass +class Position: + x: int = 0 + y: int = 0 + + +def get_position(grid: List[List[str]], char: str) -> Position: + y = grid.index_of(grid.where(lambda row: char in row).single()) + x = grid.element_at(y).index_of(char) + return Position(x, y) + + +def get_path(grid: List[List[Union[str, int]]], start: Position, reverse=False): + width = grid.first().count() + height = grid.count() + directions = [(0, 1), (0, -1), (1, 0), (-1, 0)] + + paths = collections.defaultdict(lambda: 10e15) + paths[(start.y, start.x)] = 0 + should_search = [(start.x, start.y, 0)] + while len(should_search) > 0: + x, y, steps = should_search[0] + should_search = should_search[1:] + from_height = ord(grid[y][x]) + + for (dx, dy) in directions: + nx = x + dx + ny = y + dy + if nx < 0 or nx >= width or ny < 0 or ny >= height: + continue + + to_height = ord(grid[ny][nx]) + + if not reverse and not from_height - to_height >= -1: + continue + + if reverse and not from_height - to_height <= 1: + continue + + if paths[(ny, nx)] > steps + 1: + paths[(ny, nx)] = steps + 1 + should_search.append((nx, ny, steps + 1)) + + return paths + + +def main(): + grid = List(str, aoc_input.splitlines()).select(lambda x: List(int, x)) + Console.write_line(grid) + start = get_position(grid, 'S') + target = get_position(grid, 'E') + grid: List[List[Union[str, int]]] = grid.select(lambda x: x.select(lambda y: 'a' if y == 'S' else 'z' if y == 'E' else y)) + Console.write_line(get_path(grid, start)[target.y, target.x]) + Console.write_line(min([dist for ((y, x), dist) in get_path(grid, target, True).items() if grid[y][x] == 'a'])) + + +if __name__ == '__main__': + Console.write_line(f'Advent of code day {day}') + main() + Console.write_line()