June 2018 Update

Task/Vampire-number/Sidef/vampire-number.sidef

@@ -0,0 +1,39 @@
+func is_vampire (n) {
+    return [] if n.ilog10.is_even
+
+    var l1 = n.isqrt.ilog10.ipow10
+    var l2 = n.isqrt
+
+    var s = n.digits.sort.join
+
+    gather {
+        n.divisors.each { |d|
+
+            d < l1 && next
+            d > l2 && break
+
+            var t = n/d
+
+            next if (d%%10 && t%%10)
+            next if ("#{d}#{t}".sort != s)
+
+            take([d, t])
+        }
+    }
+}
+
+say "First 25 Vampire Numbers:"
+
+with (1) { |i|
+    for (var n = 1; i <= 25; ++n) {
+        var fangs = is_vampire(n)
+        printf("%2d. %6s : %s\n", i++, n, fangs.join(' ')) if fangs
+    }
+}
+
+say "\nIndividual tests:"
+
+[16758243290880, 24959017348650, 14593825548650].each { |n|
+    var fangs = is_vampire(n)
+    say "#{n}: #{fangs ? fangs.join(', ') : 'is not a vampire number'}"
+}