day11_part2.py

day11_part2.py

#!/usr/bin/env python3


def build_map() -> list[list[str]]:
    with open("input.txt") as f:
        rows = []
        for line in f:
            line = list(line.strip())
            elems = set(line)
            if len(elems) == 1 and '.' in elems:
                rows.append(['*'] * len(line))
            else:
                rows.append(line)

    for j in range(len(rows[0])):
        only_dots = True
        for i in range(len(rows)):
            if not rows[i][j] in {'.', '*', }:
                only_dots = False
        
        if only_dots:
            for i in range(len(rows)):
                rows[i][j] = '*'
    
    return rows


def find_galaxies(map: list[list[str]]) -> list[tuple[int, int]]:
    return [(i, j) for i, row in enumerate(map) for j, ch in enumerate(row) if ch == '#']


def sum_of_distances(galaxies: list[tuple[int, int]], map: list[list[str]]) -> int:
    ans = 0

    for i, (x1, y1) in enumerate(galaxies[:-1]):
        for j, (x2, y2) in enumerate(galaxies[i + 1:], start=i + 1):
            current = 0
            for i in range(min(x1, x2), max(x1, x2)):
                current += 1000000 if map[i][y1] == '*' else 1
            for j in range(min(y1, y2), max(y1, y2)):
                current += 1000000 if map[x1][j] == '*' else 1
                
            ans += current

    return ans

map = build_map()
galaxies = find_galaxies(map)
print(sum_of_distances(galaxies, map))