Scala example solutions for Project Euler problem 001

ProjectEulerProblem1.scala

/**
 * <p>If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples
 * is 23.
 * 
 * <p>Find the sum of all the multiples of 3 or 5 below 1000.
 * 
 * @author Adrian K. <[email protected]>
 */
object ProjectEulerProblem001 {
    def main( args : Array[String] ) : Unit = {
        // Solution 1
        println( (
                for ( i <- List.range( 1, 1000 ) if i % 3 == 0 || i % 5 == 0 ) yield i
            ).reduceLeft[Int]( _+_ ) // same as .reduceLeft[Int]( ( a:Int, b:Int ) => a + b )
        )
        // Solution 2
        println(
            ( 1 to 999 ).foldLeft( 0 ) { ( total, x ) => 
                x match {
                    case i if ( i % 3 == 0 || i % 5 ==0 ) => i + total
                    case _ => total
                }
            }
        )
    }
}