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Add day 1 part 2

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RGBCube 2023-12-01 23:40:12 +03:00
parent 3a223b8219
commit dfda2c002c
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4 changed files with 1047 additions and 4 deletions
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{ lib, input }:
with builtins; with lib; rec {
digits = {
zero = "0";
one = "1";
two = "2";
three = "3";
four = "4";
five = "5";
six = "6";
seven = "7";
eight = "8";
nine = "9";
};
toDigit = maybeDigit: if digits ? "${maybeDigit}" then
digits.${maybeDigit}
else
maybeDigit;
allNeedles = flatten (mapAttrsToList (key: value: [ key (toString value) ]) digits);
allNeedlesReverse = map reverseString allNeedles;
reverseString = string: concatStrings (reverseList (stringToCharacters string));
firstMatch = haystack: needles: let
prefixNeedle = findFirst (needle: hasPrefix needle haystack) null needles;
in if prefixNeedle != null then
prefixNeedle
else
firstMatch (substring 1 (stringLength haystack - 1) haystack) needles;
firstLast = line: let
first = firstMatch line allNeedles;
last = reverseString (firstMatch (reverseString line) allNeedlesReverse);
in fromJSON (toDigit first + toDigit last);
lines = splitString "\n" input;
result = foldl' add 0 (map firstLast lines);
}