Reorganize makefile and scripts.

benchmark/fannkuch.lua

@@ -0,0 +1,48 @@
+-- The Computer Language Benchmarks Game
+-- http://benchmarksgame.alioth.debian.org/
+-- contributed by Mike Pall
+
+local function fannkuch(n)
+  local p, q, s, sign, maxflips, sum = {}, {}, {}, 1, 0, 0
+  for i=1,n do p[i] = i; q[i] = i; s[i] = i end
+  repeat
+    -- Copy and flip.
+    local q1 = p[1]       -- Cache 1st element.
+    if q1 ~= 1 then
+      for i=2,n do q[i] = p[i] end    -- Work on a copy.
+      local flips = 1
+      repeat
+  local qq = q[q1]
+  if qq == 1 then       -- ... until 1st element is 1.
+    sum = sum + sign*flips
+    if flips > maxflips then maxflips = flips end -- New maximum?
+    break
+  end
+  q[q1] = q1
+  if q1 >= 4 then
+    local i, j = 2, q1 - 1
+    repeat q[i], q[j] = q[j], q[i]; i = i + 1; j = j - 1; until i >= j
+  end
+  q1 = qq; flips = flips + 1
+      until false
+    end
+    -- Permute.
+    if sign == 1 then
+      p[2], p[1] = p[1], p[2]; sign = -1  -- Rotate 1<-2.
+    else
+      p[2], p[3] = p[3], p[2]; sign = 1   -- Rotate 1<-2 and 1<-2<-3.
+      for i=3,n do
+  local sx = s[i]
+  if sx ~= 1 then s[i] = sx-1; break end
+  if i == n then return sum, maxflips end -- Out of permutations.
+  s[i] = i
+  -- Rotate 1<-...<-i+1.
+  local t = p[1]; for j=1,i do p[j] = p[j+1] end; p[i+1] = t
+      end
+    end
+  until false
+end
+
+local n = 9
+local sum, flips = fannkuch(n)
+io.write(sum, "\nPfannkuchen(", n, ") = ", flips, "\n")