Data commit

Task/Digital-root/Wren/digital-root.wren

@@ -0,0 +1,30 @@
+import "/fmt" for Fmt
+
+var sumDigits = Fn.new { |n|
+    var sum = 0
+    while (n > 0) {
+        sum = sum + (n%10)
+        n = (n/10).floor
+    }
+    return sum
+}
+
+var digitalRoot = Fn.new { |n|
+    if (n < 0) Fiber.abort("Argument must be non-negative.")
+    if (n < 10) return [n, 0]
+    var dr = n
+    var ap = 0
+    while (dr > 9) {
+        dr = sumDigits.call(dr)
+        ap = ap + 1
+    }
+    return [dr, ap]
+}
+
+var a = [1, 14, 267, 8128, 627615, 39390, 588225, 393900588225]
+for (n in a) {
+    var res = digitalRoot.call(n)
+    var dr = res[0]
+    var ap = res[1]
+    Fmt.print("$,15d has additive persistence $d and digital root of $d", n, ap, dr)
+}