Sciss · October 31, 2021 22:36
diff --git a/ISBN13_CheckSum.scala b/ISBN13_CheckSum.scala
 val s = "978-3-9504622-3-"
 val s0 = s.filter(_.isDigit)
 val u = (s0 zip Iterator.continually(Seq(1, 3)).flatten).map { case (c, m) => c.toString.toInt * m } .sum
 val v = u.roundUpTo(10)
 val p = v - u // 4
 s ++ p.toString // "978-3-9504622-3-4"
	val s = "978-3-9504622-3-"
	val s0 = s.filter(_.isDigit)
	val u = (s0 zip Iterator.continually(Seq(1, 3)).flatten).map { case (c, m) => c.toString.toInt * m } .sum
	val v = u.roundUpTo(10)
	val p = v - u // 4
	s ++ p.toString // "978-3-9504622-3-4"