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Advent of Code 2020: Python Solution Day 17

qviper profile image Viper ・2 min read

I feel ashamed now because I could not understand problem correctly. And I basically copied pasted code from here and then refactored a little bit. So all the credit goes to the author.

Part 1

def part1():
    with open("day17.txt") as fp:
        lines = [fline.rstrip() for fline in fp.readlines()]

    f = lines 
    cubes = {(i, j, 0):lines[i][j] 
             for i in range(len(lines)) 
             for j in range(len(lines[0]))}
    for i in range(6):
        cubes = simulate(cubes)

    print(f"Part 1 Solution: {list(cubes.values()).count('#')}")


def simulate(cubes):
    new_cube = {}
    for c in cubes:
        x = checkNeighbors(c, cubes)
        if cubes[c] == '#':
            if x == 2 or x == 3:
                new_cube[c] = '#'
            else:
                new_cube[c] = '.'
            n = findNeighbors(c)
            for x in n:
                if x not in cubes:
                    k = checkNeighbors(x, cubes)
                    if k == 3:
                        new_cube[x] = '#'
        elif cubes[c] == '.':
            if x == 3:
                new_cube[c] = '#'
            else:
                new_cube[c] = '.'
    return new_cube


def findNeighbors(c):
    neighbors = [(c[0]+i, c[1]+j, c[2]+k) 
                 for i in range(-1, 2) 
                 for j in range(-1, 2) 
                 for k in range(-1, 2) 
                 if not (i == 0 and j == 0 and k == 0)]
    return neighbors


def checkNeighbors(c, cubes):
    n = findNeighbors(c)
    neighbors_count = len([x for x in n if cubes.get(x)=="#"])
    return neighbors_count
part1()
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def part2():
    with open("day17.txt") as fp:
        lines = [fline.rstrip() for fline in fp.readlines()]
    f = lines 
    cubes = {(i, j, 0, 0):lines[i][j] 
             for i in range(len(lines)) 
             for j in range(len(lines[0]))}
    for i in range(6):
        cubes = simulate4d(cubes)

    print(f"Part 2 Solution: {list(cubes.values()).count('#')}")


def simulate4d(cubes):
    new = {}
    for c in cubes:
        x = checkNeighbors4d(c, cubes)
        if cubes[c] == '#':
            if x == 2 or x == 3:
                new[c] = '#'
            else:
                new[c] = '.'
            n = findNeighbors4d(c)
            for x in n:
                if x not in cubes:
                    k = checkNeighbors4d(x, cubes)
                    if k == 3:
                        new[x] = '#'
        elif cubes[c] == '.':
            if x == 3:
                new[c] = '#'
            else:
                new[c] = '.'
    return new


def findNeighbors4d(c):
    neighbors = [(c[0]+i, c[1]+j, c[2]+k, c[3]+w) 
                 for i in range(-1, 2) 
                 for j in range(-1, 2) 
                 for k in range(-1, 2) 
                 for w in range(-1, 2) 
                 if not (i == 0 and j == 0 and k == 0 and w == 0)]
    return neighbors


def checkNeighbors4d(c, cubes):
    n = findNeighbors4d(c)
    neighbors_count = len([x for x in n if cubes.get(x)=="#"])
    return neighbors_count
part2()
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