June 2018 Update

Task/Digital-root/Elena/digital-root.elena

@@ -0,0 +1,30 @@
+import extensions.
+import system'routines.
+
+extension $op
+{
+    digitalRoot
+    [
+        int  additivepersistence := 0.
+        long num := self.
+
+        while (num > 9)
+        [
+            num := num literal; toArray; selectBy(:ch)(ch toInt - 48); summarize(LongInteger new).
+
+            additivepersistence += 1.
+        ].
+
+        ^ { item1 = additivepersistence. item2 = num toInt. }.
+    ]
+}
+
+program =
+[
+    (627615l, 39390l, 588225l, 393900588225l) forEach(:num)
+    [
+        var t := num digitalRoot.
+
+        console printLineFormatted("{0} has additive persistence {1} and digital root {2}", num, t item1, t item2).
+    ]
+].