AoC 2021 Day 15: Low Ceiling Simulator

2021-12-15

Source: Chiton

Part 1: Given a grid of weights, find the minimum path from top left to top right. Return the total weight along that path.

AoC 2021 Day 14: Polymerizationinator

2021-12-14

Source: Extended Polymerization

Part 1: Given a complete function `f(a, b) -> c` where any string `ab` becomes `acb` and an input string, apply the function at the same time to every (overlapping) pair of letters. Repeat this time times. Report the difference in counts between the most and least common letters in the final situation.

AoC 2021 Day 13: Foldinator

2021-12-13

Source: Transparent Origami

Part 1: Given a set of points and a sequence of ‘fold’ lines (where you either fold the bottom over the top or right over left), determine how many points exist after the first fold.

AoC 2021 Day 12: Submarine Spider

2021-12-12

Source: Passage Pathing

Part 1: Given a list of edges in a bi-directional graph, count the number of paths from `start` to `end` such that nodes named with lowercase letters are visited once, and nodes with uppercase letters can be visited any number of times.

AoC 2021 Day 11: Octopus Flashinator

2021-12-11

Source: Dumbo Octopus

Part 1: Simulate a grid of numbers such that on each tick: advance all numbers by 1, any number that increases over 9 will ‘flash’ and add 1 to all neighbors (recursively, but each cell can only flash once) and then reset to 0. Count the number of flashes in the first 100 ticks.

AoC 2021 Day 10: Chunkinator

2021-12-10

Source: Syntax Scoring

Part 1: Given a sequence of () [] {}, and <> with nesting allowed. Find the first syntax error (where the wrong closing symbol is used). Scoring 3, 57, 1197, and 25137 respectively for each error, calculate the total error score.

AoC 2021 Day 9: Local Minimum Deminifier

2021-12-09

Source: Smoke Basin

Part 1: Given a heightmap, find all local minimums. Return the sum of (minimum height + 1) for each local minimum.

AoC 2021 Day 8: Seven Segment Demystifier

2021-12-08

Source: Seven Segment Search

Part 1: Simulate a seven segment displey where you do not know which input wire controls which segment. Given the wires used in all ten digits and four output digits, count how many times 1, 4, 7, and 8 are outputted.

AoC 2021 Day 7: Brachyura Aligner

2021-12-07

Source: The Treachery of Whales

Part 1: Given a list of numbers, find the minimum integer `I` such the sum difference of each number and I is minimized.

AoC 2021 Day 6: We All Glow Down Here

2021-12-06

Source: Latternfish

Part 1: Simulate a population of lanternfish. Each fish is immortal, starts having children after 9 days, and has another child after 7 more days. Calculate the number of fish after 80 days.

Source: Chiton

Part 1: Given a grid of weights, find the minimum path from top left to top right. Return the total weight along that path.

Source: Extended Polymerization

Part 1: Given a complete function f(a, b) -> c where any string ab becomes acb and an input string, apply the function at the same time to every (overlapping) pair of letters. Repeat this time times. Report the difference in counts between the most and least common letters in the final situation.

Source: Transparent Origami

Part 1: Given a set of points and a sequence of ‘fold’ lines (where you either fold the bottom over the top or right over left), determine how many points exist after the first fold.

Source: Passage Pathing

Part 1: Given a list of edges in a bi-directional graph, count the number of paths from start to end such that nodes named with lowercase letters are visited once, and nodes with uppercase letters can be visited any number of times.

Source: Dumbo Octopus

Part 1: Simulate a grid of numbers such that on each tick: advance all numbers by 1, any number that increases over 9 will ‘flash’ and add 1 to all neighbors (recursively, but each cell can only flash once) and then reset to 0. Count the number of flashes in the first 100 ticks.

Source: Syntax Scoring

Part 1: Given a sequence of () [] {}, and <> with nesting allowed. Find the first syntax error (where the wrong closing symbol is used). Scoring 3, 57, 1197, and 25137 respectively for each error, calculate the total error score.

Source: Smoke Basin

Part 1: Given a heightmap, find all local minimums. Return the sum of (minimum height + 1) for each local minimum.

Source: Seven Segment Search

Part 1: Simulate a seven segment displey where you do not know which input wire controls which segment. Given the wires used in all ten digits and four output digits, count how many times 1, 4, 7, and 8 are outputted.

Source: The Treachery of Whales

Part 1: Given a list of numbers, find the minimum integer I such the sum difference of each number and I is minimized.

Source: Latternfish

Part 1: Simulate a population of lanternfish. Each fish is immortal, starts having children after 9 days, and has another child after 7 more days. Calculate the number of fish after 80 days.

Part 1: Given a list of edges in a bi-directional graph, count the number of paths from `start` to `end` such that nodes named with lowercase letters are visited once, and nodes with uppercase letters can be visited any number of times.

Part 1: Given a list of numbers, find the minimum integer `I` such the sum difference of each number and I is minimized.