package kapitel_01

/**
 * Beispiel aus
 *
 * - Algorithmen und Datenstrukturen für Dummies
 *   - von Andreas Gogol-Döring und Thomas Letschert
 *   - Verlag Wiley-VCH; Oktober 2019
 *  - Kapitel 1, Das sind Algorithmen
 *
 * @author A. Gogol-Döring, Th. Letschert
 */
object AuD_01_03_Riddle_App extends App {

  def Riddle(n: Int, m:Int): Int = {
    var x = n
    var y = m
    var p = 0
    println("  n  |    m  |   x  |   y  |   p ")
    println(s"-----+-------+------+------+-----")
    while (x >= 1) {
      println(f"$n%4.0f | $m%4.0f  | $x%4.0f | $y%4.0f | $p%4.0f")
      assert(n * m == x * y + p)
      if (x % 2 == 0) {
        x = x / 2
      } else {
        p = p + y
        x = (x - 1) / 2
      }
      y = 2 * y
    }
    println(f"$n%4.0f | $m%4.0f  | $x%4.0f | $y%4.0f | $p%4.0f")

    p
  }

  def product(n: Int, m:Int): Int = {
    var x = n
    var p = 0
    println( "  n  |    m  |   x  |   p ")
    println(s"-----+-------+------+-----")
    while (x >= 1) {
      println(f"$n%4.0f | $m%4.0f  | $x%4.0f | $p%4.0f")
      assert(n * m == x * m + p)
      p = p + m
      x = x - 1
    }
    println(f"$n%4.0f | $m%4.0f  | $x%4.0f | $p%4.0f")
    p
  }

  val prod1 = product(5, 6)

  println()

  println(s"5*6 = $prod1")


  val prod2 = Riddle(5, 6)

  println()

  println(s"5*6 = $prod2")


}