2023/day05.py

import fileinput
import sys


def parse_map(input):
    try:
        while line := next(input).strip():
            yield tuple(int(n) for n in line.strip().split())
        next(input)
    except StopIteration:
        pass

    yield (0, 0, sys.maxsize)


def transform_ranges(map, ranges):
    for start, length in ranges:
        # find the start of the range
        (dst_start, src_start, len) = next(
            (dst, src, len)
            for (dst, src, len) in map
            if src <= start < (src + len)
        )

        end = start + length
        src_end = src_start + len

        # yield the starting range
        yield (dst_start + start - src_start, min(src_end, end) - start)

        # if range is not complete, recurse into the rest
        if end > src_end:
            yield from transform_ranges(map, [(src_end, end - src_end)])


def do_the_thing(maps, ranges):
    for map in maps:
        ranges = transform_ranges(map, ranges)
    return min(ranges)[0]


def main():
    input = fileinput.input()

    seeds = [int(seed) for seed in next(input).split()[1:]]
    next(input)
    next(input)

    maps = [list(parse_map(input)) for _ in range(7)]

    part1 = do_the_thing(maps, ((seed, 1) for seed in seeds))
    part2 = do_the_thing(maps, zip(*[iter(seeds)] * 2))

    print(part1, part2)

main()