Ruby solution for week 108, part 2

1 files changed, 39 insertions, 0 deletions

diff --git a/challenge-108/abigail/ruby/ch-2.rb b/challenge-108/abigail/ruby/ch-2.rb
new file mode 100644
index 0000000000..184a0dcc66
--- /dev/null
+++ b/challenge-108/abigail/ruby/ch-2.rb
@@ -0,0 +1,39 @@
+#!/usr/bin/ruby
+
+#
+# See ../README.md
+#
+ 
+#
+# Run as: ruby ch-2.rb
+#
+
+COUNT   = 10
+PLAIN   =  0
+COMPUTE =  1
+
+type = PLAIN
+
+if   ARGV . length > 0 && ARGV[0] == "compute"
+then type = COMPUTE
+end
+
+if   type == PLAIN
+then puts ("1, 1, 2, 5, 15, 52, 203, 877, 4140, 21147");
+end
+
+if   type == COMPUTE
+then bell = [[1]]
+     for  x in 1 .. COUNT - 2
+          bell [x] = [bell [x - 1] [x - 1]]
+          for  y in 1 .. x
+               bell [x] [y] = bell [x] [y - 1] + bell [x - 1] [y - 1]
+          end
+     end
+     print (1)
+     for  x in 0 .. COUNT - 2
+          print (", ")
+          print (bell [x] [x])
+     end
+     puts ("")
+end