aoc2023/day12.py

from tools.aoc import AOCDay
from tools.int_seq import triangular
from typing import Any


def get_arrangements(springs: str, groups: list[int]):
    springs, not_found = clean_springs(springs, groups)
    print("not_found", not_found)
    open_groups = get_open_groups(springs)
    to_determine = []
    for start, group_str in open_groups:
        print("look in", group_str, "for", [groups[x[2]] for x in not_found])
        assigned = []
        for min_x, max_x, idx_need in list(not_found):
            print("check", min_x, "<", start, "<", max_x, idx_need, groups[idx_need])
            if groups[idx_need] > len(group_str):
                continue
            elif (not assigned or sum(assigned) + len(assigned) + groups[idx_need] <= len(group_str)) and (
                min_x <= start <= max_x
            ):
                assigned.append(groups[idx_need])
                not_found = not_found[1:]
            else:
                break
        print("append", assigned)
        if assigned:
            to_determine.append((group_str, assigned))

    arrangements = 1
    for group_str, values in to_determine:
        if len(values) == 1 and len(group_str) == values[0]:
            continue
        elif sum(values) + len(values) - 1 == len(group_str):
            continue
        elif len(values) == 1:
            arrangements *= len(group_str) - values[0] + 1
        else:
            arrangements *= triangular(len(group_str) - (sum(values) + len(values) - 1) + 1)
            # print(
            #    group_str,
            #    "with",
            #    values,
            #    "has multiple options:",
            #    triangular(len(group_str) - (sum(values) + len(values) - 1) + 1),
            # )

    if arrangements < 0:
        print(springs, groups, to_determine)
        exit(1)

    return arrangements


def clean_springs(springs: str, groups: list[int]) -> (str, list[int]):
    hashes = []
    start = None
    c_size = 0
    for i, c in enumerate(springs):
        if c == "#":
            if start is None:
                start = i
            c_size += 1
        else:
            if start is not None:
                hashes.append((start, c_size))
                start = None
                c_size = 0

    if start is not None:
        hashes.append((start, c_size))

    print("cleaning", springs, "with hashes", hashes, "and groups", groups)
    found = {}
    for i, s in enumerate(groups):
        for h in hashes:
            if h[0] >= sum(groups[:i]) + i and h[0] <= len(springs) - (sum(groups[i:]) + len(groups) - i) + 1:
                # print(h[0], ">", sum(groups[:i]) + i)
                # print(h[0], "<", len(springs) - (sum(groups[i:]) + len(groups) - i) + 1)
                if h[1] == s:
                    found[i] = (h[0], s)
                    if h[0] == 0:
                        springs = "#" * h[1] + "." + springs[h[0] + h[1] + 1 :]
                    elif h[0] + h[1] == len(springs):
                        springs = springs[: -(h[1] + 1)] + "." + "#" * h[1]
                    else:
                        springs = springs[: h[0] - 1] + "." + "#" * h[1] + "." + springs[h[0] + h[1] + 1 :]
                    print(
                        "found index",
                        i,
                        "value",
                        groups[i],
                        "at",
                        h[0],
                        "new springs",
                        springs,
                    )
                break

    print("cleaned springs", springs, "found", found)
    not_found = []
    # not_found entry = (min_x, max_x, index)
    nf = []
    last_min = 0
    for i in range(len(groups)):
        if i in found:
            if nf:
                for x in nf:
                    not_found.append((last_min, found[i][0], x))
            nf = []
            last_min = sum(found[i])
        else:
            nf.append(i)
    if nf:
        for x in nf:
            not_found.append((last_min, len(springs), x))

    return springs, not_found


def get_open_groups(springs: str) -> list[tuple[int, str]]:
    open_groups = []
    start = None
    group_str = ""
    for i, c in enumerate(springs):
        if c == ".":
            if "?" in group_str:
                open_groups.append((start, group_str))
            start = None
            group_str = ""
        else:
            if start is None:
                start = i
            group_str += c

    if "?" in group_str:
        open_groups.append((start, group_str))

    return open_groups


class Day(AOCDay):
    inputs = [
        [
            (21, "input12_test"),
            (6981, "input12"),
        ],
        [
            (525152, "input12_test"),
            (None, "input12"),
        ],
    ]

    def part1(self) -> Any:
        ans = 0
        for line in self.getInput():
            springs, groups = line.split()
            groups = list(map(int, groups.split(",")))
            f = get_arrangements(springs, groups)
            print("RESULT", springs, "=>", f)
            ans += f

        return ans

    def part2(self) -> Any:
        return ""
        ans = 0
        for i, line in enumerate(self.getInput()):
            springs, groups = line.split()
            groups = list(map(int, groups.split(",")))
            springs = "?".join([springs] * 5)
            groups = groups * 5
            f = get_arrangements(springs, groups)
            print(i + 1, "/", len(self.input), "=>", f)
            ans += f

        return ans


if __name__ == "__main__":
    day = Day(2023, 12)
    day.run(verbose=True)