advent-of-code/src/holt59/aoc/2023/day1.py

from typing import Any, Iterator

from ..base import BaseSolver


def find_values(lines: list[str], lookups: dict[str, int]) -> list[int]:
    values: list[int] = []

    for line in filter(bool, lines):
        first_digit = min(
            lookups,
            key=lambda lookup: index
            if (index := line.find(lookup)) >= 0
            else len(line),
        )
        last_digit = max(
            lookups,
            key=lambda lookup: index if (index := line.rfind(lookup)) >= 0 else -1,
        )

        values.append(10 * lookups[first_digit] + lookups[last_digit])

    return values


class Solver(BaseSolver):
    def solve(self, input: str) -> Iterator[Any]:
        lookups_1 = {str(d): d for d in range(1, 10)}
        lookups_2 = lookups_1 | {
            d: i + 1
            for i, d in enumerate(
                (
                    "one",
                    "two",
                    "three",
                    "four",
                    "five",
                    "six",
                    "seven",
                    "eight",
                    "nine",
                )
            )
        }

        lines = input.splitlines()

        yield sum(find_values(lines, lookups_1))
        yield sum(find_values(lines, lookups_2))