Advent of Code 2024, day 10

AdventOfCode2024.Day10.py

import sys
from itertools import combinations

sys.setrecursionlimit(10**6)

with open("./data/input10.txt") as inputFile:
    input = inputFile.read().splitlines()

trailheads = []
grid = []
for r in range(len(input)):
    row = []
    for c in range(len(input[r])):
        n = int(input[r][c])
        if n == 0: trailheads.append((r,c))
        row.append(int(input[r][c]))
    grid.append(row)

def get_neighbors(grid, pt):
    neighbors = []
    for r in range(max(0, pt[0]-1), min(len(grid), pt[0]+2)):
        for c in range(max(0, pt[1]-1), min(len(grid[r]), pt[1]+2)):
            if not (r == pt[0] and c == pt[1]) and (r == pt[0] or c == pt[1]):
                neighbors.append((r,c))
    return neighbors

def get_paths(grid, start, condition):
    paths = []
    for point in get_neighbors(grid, start):
        if condition(grid[point[0]][point[1]], grid[start[0]][start[1]]):
            for subpath in get_paths(grid, point, condition):
                paths.append([start] + subpath)
    if len(paths) == 0:
        return [[start]]
    else:
        return paths

res1 = 0
res2 = 0
for th in trailheads:
    s = set()
    for t in get_paths(grid, th, lambda x, y: x == y+1):
        if len(t) == 10:
            s.add(t[9])
            res2 += 1
    res1 += len(s)

# Part 1:
print(res1)

# Part 2:
print(res2)