Advent of Code 2024 - Day 10

# Part 1

from future import annotations

import dataclasses import typing

@dataclasses.dataclass(frozen=True) class Vector: y: int x: int

def __add__(self, b):
    return Vector(self.y + b.y, self.x + b.x)

def is_valid(self, grid: list[list[int]]) -> bool:
    if self.x < 0:
        return False
    elif self.y < 0:
        return False
    elif self.x >= len(grid[0]):
        return False
    elif self.y >= len(grid):
        return False
    else:
        return True

def get_data(path: str) -> typing.Iterator[list[int]]: with open(path) as f: for line in f: yield [int(x) for x in line.strip()]

def main(data: typing.Iterator[list[int]]): grid = list(data)

stack = []
for y, row in enumerate(grid):
    for x, c in enumerate(row):
        if c == 0:
            stack.append((Vector(y, x), Vector(y, x)))

seen_paths = set()
paths = 0
while stack:
    pos, initial = stack.pop()
    current_elevation = grid[pos.y][pos.x]

    if current_elevation == 9:
        key = (pos, initial)
        if key not in seen_paths:
            paths += 1
            seen_paths.add(key)
        continue

    for delta in [
            Vector(1, 0),
            Vector(-1, 0),
            Vector(0, 1),
            Vector(0, -1)
    ]:
        next_position = pos + delta
        if not next_position.is_valid(grid):
            continue

        if grid[next_position.y][next_position.x] == current_elevation + 1:
            stack.append((next_position, initial))

return paths

if name == “main”: # print(main(get_data(“day_10_input_test.txt”))) print(main(get_data(“day_10_input.txt”)))

## Part 2
from __future__ import annotations

import dataclasses
import typing

@dataclasses.dataclass(frozen=True)
class Vector:
    y: int
    x: int

    def __add__(self, b):
        return Vector(self.y + b.y, self.x + b.x)

    def is_valid(self, grid: list[list[int]]) -> bool:
        if self.x < 0:
            return False
        elif self.y < 0:
            return False
        elif self.x >= len(grid[0]):
            return False
        elif self.y >= len(grid):
            return False
        else:
            return True

def get_data(path: str) -> typing.Iterator[list[int]]:
    with open(path) as f:
        for line in f:
            yield [int(x) for x in line.strip()]

def main(data: typing.Iterator[list[int]]):
    grid = list(data)

    stack = []
    for y, row in enumerate(grid):
        for x, c in enumerate(row):
            if c == 0:
                stack.append(Vector(y, x))

    paths = 0
    while stack:
        pos = stack.pop()
        current_elevation = grid[pos.y][pos.x]

        if current_elevation == 9:
            paths += 1
            continue

        for delta in [
                Vector(1, 0),
                Vector(-1, 0),
                Vector(0, 1),
                Vector(0, -1)
        ]:
            next_position = pos + delta
            if not next_position.is_valid(grid):
                continue

            if grid[next_position.y][next_position.x] == current_elevation + 1:
                stack.append(next_position)

    return paths


if __name__ == "__main__":
    print(main(get_data("day_10_input_test.txt")))
    print(main(get_data("day_10_input.txt")))