March 2014 update

Task/Pi/Haskell/pi-2.hs

@@ -0,0 +1,18 @@
+#!/usr/bin/runhaskell
+
+import Control.Monad
+import System.IO
+
+pi_ = g(1,0,1,1,3,3) where
+  g (q,r,t,k,n,l) =
+   if 4*q+r-t < n*t
+    then n : g (10*q, 10*(r-n*t), t, k, div (10*(3*q+r)) t - 10*n, l)
+    else g (q*k, (2*q+r)*l, t*l, k+1, div (q*(7*k+2)+r*l) (t*l), l+2)
+
+digs = insertPoint digs'
+  where insertPoint (x:xs) = x:'.':xs
+        digs' = map (head . show) pi_
+
+main = do
+  hSetBuffering stdout $ BlockBuffering $ Just 80
+  forM_ digs putChar