Advent of Code 2020

Welcome to my AoC 2020 solutions!

All 25 days for 2020 have working Python solutions in the repository, though I haven’t written full individual walkthrough pages for each day on this site yet. Each folder below links straight to the solution script on GitHub:

Source Code Index

Day	Technique / Topic	Source Code
1	Combinations adding to target sum	d01_combos_adding_to_sum
2	Password validation, classes and regex	d02_pwd_validation_class_regex
3	Mapping trees on a repeating grid	d03_mapping_trees
4	Passport validation and sets	d04_passport_validation_and_sets
5	Binary boarding passes and sets	d05_binary_boardig_passes_and_sets
6	Customs forms and set splatting	d06_customs_form_set_splatting
7	Recursive bags and directed graphs	d07_recursive_bags_and_graphs
8	Basic CPU simulation	d08_basic_CPU_sim
9	Sliding window with deque	d09_sliding_window_with_deque
10	Joltage adapters with defaultdict	d10_jolts_with_defaultdict
11	Seat modelling with vectors and slicing	d11_seat_modelling_with_vectors_and_slicing
12	Ship navigation, unit vectors and visualisation	d12_navigation_unit_square_and_vis
13	Bus schedules, primes and LCM	d13_bus_schedule_primes_and_lcm
14	Bitmasks, permutations and zfill	d14_bitmaks_set_clear_perms_and_zfill
15	Memory game and dict comprehensions	d15_mem_game_dict_comprehension
16	Ticket validation with sets	d16_ticket_validation_with_sets
17	Conway cubes and neighbour awareness	d17_conway_cubes_cell_knows_neighbours
18	Custom arithmetic with PEG and int subclassing	d18_weird_maths_peg_and_int_subclass
19	Message parsing with PEG grammars	d19_peg_message_processing
20	Jurassic Jigsaw binary edge matching	d20_jurassic_jigsaw_bin_edges
21	Allergen deduction with sets and unpacking	d21_allergens_with_sets_and_iterable_unpacking
22	Recursive card game	d22_recursive_card_game
23	Cup game with circular linked lists	d23_cup_game_circular_linked_list
24	Hexagonal grids and neighbours	d24_hexagons_and_neighbours
25	Door handshake modular exponentiation	d25_door_handshake_modulus