From 5339b86631af34a2ece857d808dc641b41aeed84 Mon Sep 17 00:00:00 2001 From: Daniel Flanagan Date: Mon, 6 Dec 2021 09:27:57 -0600 Subject: [PATCH] Day 6 --- 2021/six.nim | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 2021/six.nim diff --git a/2021/six.nim b/2021/six.nim new file mode 100644 index 0000000..8134e77 --- /dev/null +++ b/2021/six.nim @@ -0,0 +1,30 @@ +import std/[strutils, sequtils, tables, strformat] +import ./common + +const DEFAULT_DAYS = 80 +const CYCLE_DAYS = 7 +const MATURING_DAYS = 2 + +proc lanternFish(inputLines: seq[string], days = DEFAULT_DAYS): int = + var maturingFish: seq[(int, int)] + var fish = newSeq[int](CYCLE_DAYS) + for i in inputLines[0].split(',').mapIt(it.parseInt()): + inc fish[i] + for day in 0..days+1: + let daySeq = day mod CYCLE_DAYS + maturingFish.add((MATURING_DAYS+1, fish[daySeq])) + for v in maturingFish.mitems(): dec v[0] + if maturingFish[0][0] == 0: + fish[daySeq] += maturingFish[0][1] + maturingFish.delete(0) + result = fish.foldl(a + b) + +let input = 6.loadInput() +time("day 6 part 1"): echo input.lanternFish() +time("day 6 part 2"): echo input.lanternFish(256) + +when not defined(release): + let testInput = @["3,4,3,1,2"] + doAssert testInput.lanternFish(18) == 26 + doAssert testInput.lanternFish() == 5934 + doAssert testInput.lanternFish(256) == 26984457539