gistfile1.scala

package Problem2

import scala.collection.mutable.Seq

/*
 * Each new term in the Fibonacci sequence is generated 
 * by adding the previous two terms. 
 * By starting with 1 and 2, the first 10 terms will be: 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
 * By considering the terms in the Fibonacci sequence whose values do not exceed 
 * four million, find the sum of the even-valued terms.
 */

/*
 * 
 *  Usage:
 *  >> println(Problem2.Problem2.solve())
 *  4613732
 *  
 */

object Problem2 {
    
lazy val f: Stream[Int] = 
  0 #:: 1 #:: f.zip(f.tail).map(p => p._1 + p._2)
  
  /*
   * Problem solve
   */
  def solve() : Long = {
      return f.view.takeWhile(_ <= 4000000).filter(_ % 2 == 0).sum
	}
}