Module aoc::year2021::day06

Lanternfish

The key observation is that all fish of the same age behave the same, so we only need to store the total of each fish per day, rather than each fish individually.

Another optimization trick is rather than modifying the array by removing the fish at day 0, then shifting each fish total down by 1, we can simply increment what we consider the head of the array modulo 9 to achieve the same effect in place.

Functions

• parse
• part1
• part2
• simulate 🔒

Type Aliases

• Input 🔒