package divideandconquer
import util.Implicits._
import scala.language.implicitConversions
/*
Given
1) An input string without any space
2) A dictionary of meaningful words
returns
A sentence that can be formed with the given input
*/
def getMeaningfulSentence(input : String)(implicit dictionary : Set[String]) : Option[List[String]] =
def isWord(word : String) : Boolean = dictionary.contains(word)
def internalFunc(possibleSentence : String) : Option[List[String]] = possibleSentence.toList match
case List() => None
case a :: List() => if(isWord(a.toString)) Some(List(a.toString)) else None
case other1 if isWord(other1.mkString("")) => Some(List(other1.mkString("")))
case other2 => (1 to other2.length).map(l =>{
if(isWord(other2.take(l)))
internalFunc(other2.drop(l).mkString("")) match
case Some(list) => Some(other2.take(l).mkString("")::list)
case None => None
else None
}).reduce((a,b) => if(a.isEmpty && b.isEmpty) None else if(a.nonEmpty) a else b)
internalFunc(input)
@main def formSentence =
val sentenceWithoutSpace = "iamlegend"
val dictionary : Set[String] = Set("i", "am","legend","and","you")
val meaningfulList : Option[List[String]]=getMeaningfulSentence(sentenceWithoutSpace)(dictionary)
meaningfulList match
case Some(list) => println(list.mkString(" "))
case None => println("A meaningful sentence cannot be formed.")
