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Task/Digital-root-Multiplicative-digital-root/Sidef/digital-root-multiplicative-digital-root.sidef

@@ -0,0 +1,23 @@
+func mdroot(n) {
+  var (mdr, persist) = (n, 0)
+  while (mdr >= 10) {
+    mdr = mdr.digits.product
+    ++persist
+  }
+  [mdr, persist]
+}
+
+say "Number: MDR  MP\n======  ===  =="
+[123321, 7739, 893, 899998].each{|n| "%6d: %3d %3d\n" \
+                           .printf(n, mdroot(n)...) }
+
+var counter = Hash()
+
+Inf.times { |i|
+  var j = i-1
+  counter{mdroot(j).first} := [] << j
+  break if counter.values.all {|v| v.len >= 5 }
+}
+
+say "\nMDR: [n0..n4]\n===  ========"
+10.times {|i| "%3d: %s\n".printf(i-1, counter{i-1}.first(5)) }