81 lines
1.9 KiB
Nix
81 lines
1.9 KiB
Nix
{ pkgs, lib }:
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with lib;
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let
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input = stringToCharacters (fileContents ./input.txt);
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foldl'' = f: l: let
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initial = take 2 l;
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in foldl f (f (elemAt initial 0) (elemAt initial 1)) (drop 2 l);
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countUntil = pred: l: let
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innerCount = list: count:
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if pred (head list)
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then count
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else innerCount (drop 1 list) (count + 1);
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in innerCount l 0;
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zip4ListsWith = f: fst: snd: trd: fth:
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genList
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(n: f (elemAt fst n) (elemAt snd n) (elemAt trd n) (elemAt fth n))
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(pipe [fst snd trd fth] [
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(map length)
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(foldl'' min)
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]);
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zip4Lists = fst: snd: trd: fth:
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zip4ListsWith (fst: snd: trd: fth: { inherit fst snd trd fth; }) fst snd trd fth;
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all4ItemsAreUnique = { fst, snd, trd, fth }: fst != snd
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&& fst != trd
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&& fst != fth
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&& snd != trd
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&& snd != fth
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&& trd != fth;
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answer1 = pipe input [
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(l: zip4Lists l (drop 1 l) (drop 2 l) (drop 3 l))
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(countUntil all4ItemsAreUnique)
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(add 4)
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toString
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];
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zipLists = lists: let
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minLength = (pipe lists [
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(map length)
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(foldl'' min)
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]);
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in genList
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(n: pipe lists [
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(map (flip elemAt n))
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(imap0 (i: nameValuePair (toString i)))
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listToAttrs
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]) minLength;
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zipNSelfWithOffset = n: offset: l:
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zipLists (map (i: drop (offset * i) l) (range 0 (n - 1)));
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allItemsAreUnique = l:
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if l == []
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then true
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else !(elem (head l) (drop 1 l))
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&& allItemsAreUnique (drop 1 l);
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answer2 = pipe input [
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(zipNSelfWithOffset 14 1)
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(map attrValues)
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(countUntil allItemsAreUnique)
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(add 14)
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toString
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];
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in pkgs.writeText "answers" ''
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Task1:
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${answer1}
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Task2:
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${answer2}
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''
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