2022/day05.py

import sys
import numpy


def main():
    inp_stacks, inp_moves = (x.split("\n") for x in sys.stdin.read().split("\n\n", 1))

    rows = (line[1::4] for line in inp_stacks[::-1] if "[" in line)
    stacks = [
        numpy.array([ord(c) for c in x if c != " "], dtype=numpy.int8)
        for x in zip(*rows)
    ]
    stacks1 = numpy.array(stacks)
    stacks2 = numpy.ndarray.copy(stacks1)

    for i, line in enumerate(inp_moves):
        if i % 10000 == 0:
            print(i, len(inp_moves), end="\r")
        if not line:
            continue

        _, a, _, b, _, c = line.split()
        n, f, t = int(a), int(b) - 1, int(c) - 1

        stacks1[t] = numpy.concatenate((stacks1[t], stacks1[f][-n:][::-1]))
        stacks1[f] = stacks1[f][:-n]

        stacks2[t] = numpy.concatenate((stacks2[t], stacks2[f][-n:]))
        stacks2[f] = stacks2[f][:-n]

    print("".join(chr(s[-1]) for s in stacks1), "".join(chr(s[-1]) for s in stacks2))


if __name__ == "__main__":
    main()