Dijkstra's algorithm in Scala

dijkstra.scala

/**
 * Created with IntelliJ IDEA.
 * User: hiroyuki
 * Date: 3/10/13
 * Time: 8:34 PM
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 */



import scala.collection.mutable.Set
import scala.collection.mutable.ArrayBuffer
case class Edge(a: Int, b: Int, d: Int)

object Main {
  val questions = (1 to 200).toArray
  val answers = new ArrayBuffer[(Int,Int)]
	val X: Array[Boolean] = Array.tabulate(201)(_ => false)
	def main(args: Array[String]){
		X(1)= true
		val A = Array.tabulate(201)(_ => 0)
		val E = readEdges()
		for(_ <- 1 until 200){
		  val dist: ArrayBuffer[(Int,Int)] = new ArrayBuffer[(Int,Int)]
		  E.foreach(e => {
		    if(X(e.a) && !X(e.b)){	//If edge (e.a,e.b) crosses between X and V-X
		      dist += ((e.b, A(e.a) + e.d))
		    }else if(X(e.b) && !X(e.a)){	//If edge (e.b,e.a) crosses between X and V-X
		   //   println(e)
		      dist += ((e.a,A(e.b) + e.d))	      
		    }
		  })
		  //println(dist.mkString)
		  val selected = dist.minBy(_._2)
		  X(selected._1) = true
		  A(selected._1) = selected._2
		  if(questions.contains(selected._1)){
		    answers += ((selected._1,A(selected._1)))
		  }
		//  println(X.filter((b:Boolean) => {b}).length)
		}
		answers.sortBy(_._1).foreach(t => {
		  printf("%d,",t._2)
		})
	}

	def readEdges(): Array[Edge] = {
	  val s = scala.io.Source.fromFile("dijkstraData.txt")
	  val arr = new ArrayBuffer[Edge]
	  for(line <- s.getLines){
	    val token = line.split('\t')
	    val a = token.head.toInt
	    token.tail.map(str => {
	      val s = str.split(",")
	      val b = s(0).toInt
	      if(a < b){
	    	arr += Edge(a,b,s(1).toInt)	        
	      }
	    })
	  }
	  arr.toArray
	}
}