adventofcode-2021-day8

adventofcode_2021_day8.py

import os


"""
  0:      1:      2:      3:      4:
 aaaa    ....    aaaa    aaaa    ....
b    c  .    c  .    c  .    c  b    c
b    c  .    c  .    c  .    c  b    c
 ....    ....    dddd    dddd    dddd
e    f  .    f  e    .  .    f  .    f
e    f  .    f  e    .  .    f  .    f
 gggg    ....    gggg    gggg    ....

  5:      6:      7:      8:      9:
 aaaa    aaaa    aaaa    aaaa    aaaa
b    .  b    .  .    c  b    c  b    c
b    .  b    .  .    c  b    c  b    c
 dddd    dddd    ....    dddd    dddd
.    f  e    f  .    f  e    f  .    f
.    f  e    f  .    f  e    f  .    f
 gggg    gggg    ....    gggg    gggg

"""

number = {
    "1": 2,
    "4": 4,
    "7": 3,
    "8": 7,
}

number_reverse = {
    2: "1",
    4: "4",
    3: "7",
    7: "8",
    5: ["3", "2", "5"],
    6: ["6", "9", "0"]
}

#
number_index = {
    "1": (2, 5),
    "4": (1, 2, 3, 5),
    "7": (0, 2, 5), 
    "8": (0, 1, 2, 3, 4, 5, 6),

    "2": (0, 2, 3, 4, 6),
    "3": (0, 2, 3, 5, 6),
    "5": (0, 1, 3, 5, 6),

    "0": (0, 1, 2, 4, 5, 6),
    "6": (0, 1, 3, 4, 5, 6),
    "9": (0, 1, 2, 3, 5, 6),
}

reverse_project = {}
for key, item in number_index.items():
    reverse_project[tuple(sorted(item))] = key

number_todo = {}


def fix(f, xs):
    new_xs = f(xs)
    if xs == new_xs:
        return xs
    return fix(f, new_xs)


def unify_helper(xs):
    new_xs = xs[:]
    for x in xs:
        for y in xs:
            if x == y:
                continue
            if x[0].issubset(y[0]):
                if x not in new_xs:
                    if x:
                        new_xs.append(x)
                if y[0]-x[0] and y[1]-x[1] and (y[0]-x[0], y[1]-x[1]) not in new_xs:
                    new_xs.append((y[0]-x[0], y[1]-x[1]))
                if y in new_xs:
                    new_xs.remove(y)

            if x[0].intersection(y[0]):
                k = x[0].intersection(y[0])
                v = x[1].intersection(y[1])

                k1 = x[0] - k
                v1 = x[1] - v

                k2 = y[0] - k
                v2 = y[1] - v

                if v:
                    if (k, v) not in new_xs:
                        new_xs.append((k, v))
                    if k1 and v1:
                        if (k1, v1) not in new_xs:
                            new_xs.append((k1, v1))
                    if k2 and v2:
                        if (k2, v2) not in new_xs:
                            new_xs.append((k2, v2))

    return new_xs

z = set(range(0, 7))
w = set('abcdefg')


def unify(xs, ys):

    len5_k = set.intersection(*[i[0] for i in ys if len(i[0]) == 5])
    len5_v = set.intersection(*[i[1] for i in ys if len(i[1]) == 5])
    xs.append((len5_k, len5_v))
    len6_k = set.intersection(*[i[0] for i in ys if len(i[0]) == 6])
    len6_v = set.intersection(*[i[1] for i in ys if len(i[1]) == 6])
    xs.append((len6_k, len6_v))
    xs = fix(unify_helper, xs)
    g = {}
    for k,v in xs:
        g[list(v)[0]] = list(k)[0]

    return g


def s1(xss):
    result = 0
    for xs, ys in xss:
        for y in ys:
            if len(y) in number.values():
                result += 1
    return result


def s2(xss):
    result = 0

    for xs, ys in xss:
        right = []
        second_todo = []
        for x in xs:
            if len(x) in number.values():
                right.append((set(sorted(number_index[number_reverse[len(x)]])),  set(sorted(x))))
            else:
                for i in number_reverse[len(x)]:
                    second_todo.append((set(number_index[i]), set(sorted(x))))

        goal = unify(right, second_todo)
        tmp_int = ''
        for y in ys:
            tmp = [goal[i] for i in y]
            tmp_str = reverse_project[tuple(sorted(tmp))]
            tmp_int+=tmp_str
        result += int(tmp_int)

    return result


def main(day, input):
    this_dir = os.path.dirname(__file__)

    sample = f"{this_dir}/{day}{input}.txt"
    with open(sample, "r") as f:
        # 0,9 -> 5,9
        xss = []
        for l in f.readlines():
            xs, ys = l.strip().split("|")
            xs = [i.strip() for i in xs.strip().split(" ")]
            ys = [i.strip() for i in ys.strip().split(" ")]
            xss.append((xs, ys))
        print(s2(xss))


if __name__ == "__main__":
    main('day8', '_sample')
    main('day8', '')