from helpers import * list_pairs = [[eval(l) for l in pair.split('\n')] for pair in read_day(day).split('\n\n')] def compare_lists(l1, l2) -> int: for e1, e2 in zip(l1, l2): if isinstance(e1, int): if isinstance(e2, int): if e1 < e2: return -1 if e1 > e2: return 1 else: comp = compare_lists([e1], e2) if comp != 0: return comp else: # e1 list if isinstance(e2, int): comp = compare_lists(e1, [e2]) if comp != 0: return comp else: comp = compare_lists(e1, e2) if comp != 0: return comp # At this point, lists are equal elementwise up to the smaller list if len(l1) > len(l2): return 1 elif len(l1) < len(l2): return -1 else: return 0 def count_ordered_pairs(list_pairs): return sum((i for i, (l1, l2) in enumerate(list_pairs, 1) if compare_lists(l1, l2) == -1)) def sort_all_and_find_dividers(list_pairs): spacers = [[[2]], [[6]]] flat = [l for ls in list_pairs + [spacers] for l in ls] flat.sort(key=cmp_to_key(compare_lists)) return prod((flat.index(spacer) + 1 for spacer in spacers)) print(f'Part 1: {count_ordered_pairs(list_pairs)}') print(f'Part 2: {sort_all_and_find_dividers(list_pairs)}')