1 files changed, 45 insertions, 0 deletions
diff --git a/benchmark/bm_so_fannkuch.rb b/benchmark/bm_so_fannkuch.rb
new file mode 100644
index 0000000000..23298a8a31
--- /dev/null
+++ b/benchmark/bm_so_fannkuch.rb
@@ -0,0 +1,45 @@
+# The Computer Language Shootout
+# http://shootout.alioth.debian.org/
+# Contributed by Sokolov Yura
+# Modified by Ryan Williams
+
+def fannkuch(n)
+   maxFlips, m, r, check = 0, n-1, n, 0
+   count = (1..n).to_a
+   perm = (1..n).to_a
+
+   while true
+      if check < 30
+         puts "#{perm}"
+         check += 1
+      end
+
+      while r != 1
+         count[r-1] = r
+         r -= 1
+      end
+
+      if perm[0] != 1 and perm[m] != n
+         perml = perm.clone #.dup
+         flips = 0
+         while (k = perml.first ) != 1
+            perml = perml.slice!(0, k).reverse + perml
+            flips += 1
+         end
+         maxFlips = flips if flips > maxFlips
+      end
+      while true
+         if r==n then return maxFlips end
+         perm.insert r,perm.shift
+         break if (count[r] -= 1) > 0
+         r += 1
+      end
+   end
+end
+
+def puts *args
+end
+
+N = 10 # (ARGV[0] || 1).to_i
+puts "Pfannkuchen(#{N}) = #{fannkuch(N)}"
+