2022 Day 13

#!/usr/bin/env python3
import sys
from typing import List
from typing import Tuple
from itertools import zip_longest
from functools import cmp_to_key

RAN_OUT = -9999999999

def get_data1(filename: str) -> List[str]:
    with open(filename,'r') as f:
        lines = f.read()
    lines = lines.split("\n\n")
    return lines

def get_data2(filename: str) -> List[str]:
    with open(filename,'r') as f:
        lines = f.read().splitlines()
    return [l for l in lines if l != '']

def compare_packets(p1,p2) -> int:
    for v1,v2 in zip_longest(p1,p2,fillvalue=RAN_OUT):
        if v1 == RAN_OUT: return -1
        if v2 == RAN_OUT: return +1
        if type(v1) == int and type(v2) == int:
            if v1 < v2: return -1
            if v1 > v2: return +1
        elif type(v1) == list and type(v2) == list:
            outcome = compare_packets(v1,v2)
            if outcome is not None: return outcome
        elif type(v1) == list and type(v2) == int:
            outcome = compare_packets(v1,[v2])
            if outcome is not None: return outcome
        elif type(v1) == int and type(v2) == list:
            outcome = compare_packets([v1],v2)
            if outcome is not None: return outcome
        else:
            quit(f"Error: Unknown types: v1={type(v1)}, v2={type(v2)}")

def main():

    # Part 1
    input = get_data1(sys.argv[1])
    part1 = 0
    for ix,pair in enumerate(input):
        parts = pair.split("\n")
        first,second = parts[0], parts[1]

        first  = eval(first)
        second = eval(second)

        if compare_packets(first,second) == -1:
            part1 += ix + 1

    print(f"Part 1: {part1}") # 5760

    # Part 2
    input = get_data2(sys.argv[1])
    input.append("[[2]]")
    input.append("[[6]]")
    packets = [eval(p) for p in input]
    packets = sorted(packets, key=cmp_to_key(compare_packets))

    part2 = 1
    for ix,packet in enumerate(packets):
        if packet == [[2]]: part2 *= (ix+1)
        if packet == [[6]]: part2 *= (ix+1)
    print(f"Part 2: {part2}") # 26670


if __name__=="__main__":
    main()