Module day_11

This is my solution for Advent of Code - Day 11: Plutonian Pebbles

parse_input turns the text into numbers.

count_after_blinks solves both parts, calling count_for_stone recursively. This is cached as there are a lot of repeat small numbers at each depth. blink handles a single blink.

Statics

• COUNT_FOR_STONE 🔒
  Cached static for the count_for_stone function.

Functions

• blink 🔒
  This was originally written to work on the whole array of stones, but that wasn’t convenient for caching. It is left as is for convenience of using existing tests.
• count_after_blinks 🔒
  Solves both parts. Delegates to count_for_stone for each stone in the list.
• count_for_stone 🔒
  Recursive function to calculate the expansion of a single stone. There are many repeats, especially for small numbers, so this is cached to allow the program to run quickly.
• count_for_stone_no_cache 🔒
  Origin of the cached function count_for_stone.
• count_for_stone_prime_cache 🔒
  Primes the cached function count_for_stone. Recursive function to calculate the expansion of a single stone. There are many repeats, especially for small numbers, so this is cached to allow the program to run quickly.
• parse_input 🔒
  Turn the space separated number strings into u64s
• run
  The entry point for running the solutions with the ‘real’ puzzle input.