Advent of Code Leaderboard 2023 / Day 3

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Stick to the standard library of your language, no further dependencies/libraries, except the ones which OneCompiler provides (e.g. NumPy for Python).
Ensure your code aligns to the template (Python, Rust, Go, Kotlin, JavaScript, C#, TypeScript, C++, Java, C, Swift, Scala, Ruby), reading the puzzle input from stdin (terminated with end-of-file), and printing the solution to stdout.
Please refrain from making network requests, reading data from files, or storing data in variable/function/class names for reflection.

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Leaderboard

	Name	Language	Tokens Sum	Tokens Part 1	Tokens Part 2	Last change
1	LiquidFun	Python	555	275	280	6 months ago
2	Valentin Slawicek	Kotlin	1198	576	622	7 months ago
3	Visible-Bag4062	C++	10473	473	-	7 months ago

622 tokens in Kotlin for part 2 by Valentin Slawicek

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sealedclassCharacter(valx:Int,valy:Int)
classSymbol(x:Int,y:Int,valchar:Char,valattachedPartNumbers:MutableList<Int>=mutableListOf()):
Character(x,y)

classEmpty(x:Int,y:Int):Character(x,y)
classDigit(x:Int,y:Int,valdigit:Int,varattachedSymbol:Symbol=null):Character(x,y)

funmain(){
// Parse schematic
valschematic:List<List<Character>>=generateSequence(::readLine)
.toList()
.mapIndexed{x,line->
line.mapIndexed{y,char->
when{
char=='.'->Empty(x,y)
char.isDigit()->Digit(x,y,char.digitToInt())
else->Symbol(x,y,char)
}
}
}

fungetAdjacentCharacters(x:Int,y:Int):List<Character>{
returnlistOfNotNull(
schematic.getOrNull(x-1)?.getOrNull(y-1),
schematic.getOrNull(x-1)?.getOrNull(y),
schematic.getOrNull(x-1)?.getOrNull(y+1),
schematic.getOrNull(x)?.getOrNull(y-1),
schematic.getOrNull(x)?.getOrNull(y+1),
schematic.getOrNull(x+1)?.getOrNull(y-1),
schematic.getOrNull(x+1)?.getOrNull(y),
schematic.getOrNull(x+1)?.getOrNull(y+1),
)
}

funflagDigits(character:Character,symbol:Symbol){
getAdjacentCharacters(character.x,character.y)
.filterIsInstance<Digit>()
.filter{it.attachedSymbol==null}
.forEach{digit->
digit.attachedSymbol=symbol
flagDigits(digit,symbol)
}
}

// Traverse schematic to flag digits with its attached symbol
schematic.forEachIndexed{x,charactersLine->
charactersLine.forEachIndexed{y,character->
if(characterisSymbol){
flagDigits(character,character)
}
}
}

// Traverse schematic to get the final digit sum which have an attached symbol
vardigitSumWithAttachedSymbol=0
schematic.forEachIndexed{x,charactersLine->
valcurrentDigits=mutableListOf<Digit>()

charactersLine.forEachIndexed{y,character->
if(characterisDigit&&character.attachedSymbol!=null){
currentDigits+=character
}else{
// Treat each other character as separator
if(currentDigits.isNotEmpty()){
valpartNumber=currentDigits.joinToString(""){it.digit.toString()}.toInt()
currentDigits.first().attachedSymbol!!.attachedPartNumbers+=partNumber
digitSumWithAttachedSymbol+=partNumber
currentDigits.clear()
}
}
}
// New line is also a separator
if(currentDigits.isNotEmpty()){
valpartNumber=currentDigits.joinToString(""){it.digit.toString()}.toInt()
currentDigits.first().attachedSymbol!!.attachedPartNumbers+=partNumber
digitSumWithAttachedSymbol+=partNumber
currentDigits.clear()
}
}

println(schematic.sumOf{line->
line.sumOf{character->
(characteras?Symbol)?.attachedPartNumbers?.takeIf{it.count()==2}?.let{it[0]*it[1]}?:0
}
})
}