1 files changed, 35 insertions, 0 deletions
diff --git a/challenge-141/abigail/ruby/ch-2.rb b/challenge-141/abigail/ruby/ch-2.rb
new file mode 100644
index 0000000000..86129c8794
--- /dev/null
+++ b/challenge-141/abigail/ruby/ch-2.rb
@@ -0,0 +1,35 @@
+#!/usr/bin/ruby
+
+#
+# See ../README.md
+#
+ 
+#
+# Run as: ruby ch-2.rb < input-file
+#
+
+def substrings (n, m, prefix, max)
+    if n . length == 0 then
+        return prefix > -1  &&
+               prefix < max &&
+               prefix % m == 0 ? 1 : 0
+    end
+
+    fc   = n[0] . to_i
+    tail = n[1 .. -1]
+    if prefix == -1 then
+        n_prefix = fc
+    else
+        n_prefix = 10 * prefix + fc
+    end
+
+    return substrings(tail, m, n_prefix, max) +
+           substrings(tail, m,   prefix, max)
+end
+           
+
+ARGF . each_line do
+    | line |
+    n, m = line . strip() . split
+    puts substrings(n, m . to_i, -1, n . to_i)
+end