Data commit

Task/Happy-numbers/Scala/happy-numbers.scala

@@ -0,0 +1,24 @@
+scala> def isHappy(n: Int) = {
+     |   new Iterator[Int] {
+     |   val seen = scala.collection.mutable.Set[Int]()
+     |   var curr = n
+     |   def next = {
+     |     val res = curr
+     |     curr = res.toString.map(_.asDigit).map(n => n * n).sum
+     |     seen += res
+     |     res
+     |   }
+     |   def hasNext = !seen.contains(curr)
+     | }.toList.last == 1
+     | }
+isHappy: (n: Int)Boolean
+
+scala> Iterator from 1 filter isHappy take 8 foreach println
+1
+7
+10
+13
+19
+23
+28
+31