This repository is now superseded by alexander-held/advent-of-code.
Solutions to Advent of Code 2020 puzzles: https://adventofcode.com/2020.
What is each day about?
01
: finding values summing to specific number in list02
: password parsing, applying rules to determine valid passwords03
: 2d grid navigation, counting trees hit when taking different paths04
: passport parsing, input parsing and rule application05
: boarding pass parsing, base-2 math06
: customs forms, set unions and intersections07
: bags contained inside bags following rules / memoization08
: running game console code to calculate number, changing one instruction to make code terminate09
: subset of numbers in list that follows rules10
: adapter array to charge device, finding all possible configurations / dynamic programming11
: 2d cellular automaton: seat assignments12
: 2d grid navigation13
: coinciding bus departure times, least common multiple with offsets / Chinese remainder theorem14
: program with bitmasks15
: evaluating n-th number following game where next number depends on history16
: matching rules to list of examples following rules in unknown order to determine order of rules in example17
: 3d and 4d cellular automata18
: expression parsing with custom operator precedence19
: counting messages satisfying rules with loops / context-free grammar20
: arranging puzzle pieces to solve puzzle, finding sea monster in solved image21
: matching allergens to ingredients in list of food items / bipartite matching22
: playing 2-player card game with recursion23
: circle cup game / linked list24
: hexagonal grid navigation / cellular automaton25
: finding encryption key of handshake