31 lines
969 B
Nim
31 lines
969 B
Nim
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import std/[strutils, sequtils, tables, strformat]
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import ./common
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const DEFAULT_DAYS = 80
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const CYCLE_DAYS = 7
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const MATURING_DAYS = 2
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proc lanternFish(inputLines: seq[string], days = DEFAULT_DAYS): int =
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var maturingFish: seq[(int, int)]
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var fish = newSeq[int](CYCLE_DAYS)
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for i in inputLines[0].split(',').mapIt(it.parseInt()):
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inc fish[i]
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for day in 0..days+1:
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let daySeq = day mod CYCLE_DAYS
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maturingFish.add((MATURING_DAYS+1, fish[daySeq]))
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for v in maturingFish.mitems(): dec v[0]
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if maturingFish[0][0] == 0:
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fish[daySeq] += maturingFish[0][1]
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maturingFish.delete(0)
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result = fish.foldl(a + b)
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let input = 6.loadInput()
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time("day 6 part 1"): echo input.lanternFish()
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time("day 6 part 2"): echo input.lanternFish(256)
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when not defined(release):
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let testInput = @["3,4,3,1,2"]
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doAssert testInput.lanternFish(18) == 26
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doAssert testInput.lanternFish() == 5934
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doAssert testInput.lanternFish(256) == 26984457539
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