Scala solution for TopCoder 'SortBooks' exercise: http://community.topcoder.com/stat?c=problem_statement&pm=4557&rd=7996 #LearningScala

SortBooks.scala

object SortBooks {
  
  val lexSeparators = Set("THE","AND","OF")    
  def isABook(s:String): Boolean = {
    val words = s.split("\\s+")
  	if (words.size > 3) true else {
  		!words.map(_.toUpperCase).toSet.intersect(lexSeparators).isEmpty
  	}
  }                                              
  
  def checkManually(field1:Array[String], field2:Array[String]):Array[Int] = {
  	val bookDef = field1.zip(field2).zipWithIndex
  	val booksToCheck = bookDef.filter({case ((field1,field2),index) => !(isABook(field1) ^ isABook(field2))})
  	booksToCheck.map({case ((field1,field2),index) => index}).toArray
  }                                           
    
  val fields1 = Array( "J R R Tolkien", "THE Jungle BOOK" )
  val fields2 = Array( "THE HOBBIT", "RUDYARD KIPLING" )

  checkManually(fields1,fields2)                  //> res0: Array[Int] = Array(0)
  
}

I like the more compact form. Thanks!