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*Scala解答例 [#p9ba346f]

[[練習問題]]

解答例は次の環境でテストしています
-Scala 2.10.2
-Java 1.7.0_21 32bit
-sbt 0.12.4

ほとんどの解答例は[[ideone.com:http://ideone.com/]]でそのまま実行できます

つっこみは[[Top>/]]の避難所まで

#contents

**[[ループ練習>練習問題#eb2c4338]] [#s1c6b422]
***問1 [#ke7969de]
 object Main extends App {
   for (i <- 1 to 5) {
     println("Hello World!")
   }
 }

別解
 object Main extends App {
   (1 to 5) foreach { _ =>
     println("Hello World!")
   }
 }

***問2 [#ybb0b896]
 object Main extends App {
   val j = args(0).toInt
 
   for (i <- 1 to j) {
     println("Hello World! " + i)
   }
 }

別解
 object Main extends App {
   val j = args(0).toInt
 
   (1 to j) foreach { i =>
     println("Hello World! " + i)
   }
 }

**[[FizzBuzz>練習問題#t52e5a48]] [#ga808233]
 object Main extends App {
   def fizzBuzz(n: Int) =
     if (n % 15 == 0) {
       "FizzBuzz"
     } else if (n % 5 == 0) {
       "Buzz"
     } else if (n % 3 == 0) {
       "Fizz"
     } else {
       n.toString
     }
 
   (1 to 100).map(fizzBuzz).foreach(println)
 }

**[[素数判定>練習問題#o8db2119]] [#ldc71efe]
***判定 [#v8e35b34]
 object Main extends App {
   def prime(n: Int) =
     2 <= n && !(2 until (math.sqrt(n) + 1.0).toInt).exists(n % _ == 0)
 
   val n = args(0).toInt
 
   println(n.toString + "は" + (if (prime(n)) "素数" else "非素数"))
 }

***列挙 [#j53b2078]
 object Main extends App {
   def primes(xs: Stream[Int] = Stream.from(2)): Stream[Int] =
     xs.head #:: primes(xs.tail.filter(_ % xs.head != 0))
 
   primes() takeWhile {
     _ <= 100
   } foreach {
     println
   }
 }

**[[うるう年測定>練習問題#i0d67516]] [#xd158eb1]
 import java.util.GregorianCalendar
 
 object Main extends App {
   val cal = new GregorianCalendar()
 
   while (true) {
     print("西暦を入力してください> ")
     val y = readInt()
     if (y <= 0) sys.exit()
 
     printf("%dはうるう年%s\n", y,
       if (cal.isLeapYear(y)) "です" else "ではありません")
   }
 }

**[[転置行列>練習問題#q9f27a17]] [#o9735320]
 import scala.annotation.tailrec
 
 object Main extends App {
   type Mx = List[Array[String]]
 
   @tailrec
   def matrix(xs: Mx = Nil): Mx = {
     val sep = """\s+""".r
     val s = readLine()
     if (s.length <= 0) xs else matrix(xs :+ sep.split(s))
   }
 
   matrix().transpose.foreach(x => println(x.mkString(" ")))
 }

**[[カレンダー出力>練習問題#i5e3e061]] [#xde7305e]
-build.sbt

 name := "vipcal"
     
 version := "1.0"
     
 scalaVersion := "2.10.2"
 
 libraryDependencies ++= Seq(
     "org.scala-lang" % "scala-swing" % "2.10.2",
     "org.swinglabs.swingx" % "swingx-core" % "1.6.5-1"
 )

-Main.scala

 import scala.swing._
 import org.jdesktop.swingx.{JXDatePicker, JXMonthView}
 import java.awt.event.{ActionEvent, ActionListener}
 
 object Main extends SimpleSwingApplication {
   override lazy val top = new MainFrame with ActionListener {
     self =>
 
     val monthView = new JXMonthView()
     val datePicker = new JXDatePicker(monthView.getToday)
 
     datePicker.addActionListener(self)
 
     contents = new BoxPanel(Orientation.Vertical) {
       contents += Component.wrap(datePicker)
       contents += Component.wrap(monthView)
     }
 
     def actionPerformed(e: ActionEvent) {
       val d = datePicker.getDate
       monthView.setFirstDisplayedDay(d)
       monthView.setFlaggedDates(d)
     }
   }
 }

#ref(http://i.imgur.com/uAqI9dn.png,nolink,カレンダー)