1 files changed, 9 insertions, 0 deletions
diff --git a/21-28/25.hs b/21-28/25.hs
new file mode 100644
index 0000000..4306ae1
--- /dev/null
+++ b/21-28/25.hs
@@ -0,0 +1,9 @@
+import System.Random
+rndPermu :: [a] -> IO [a]
+
+rndPermu l = d l (length l)
+    where
+        d l@(x:xs) n | n > 0 = do i <- getStdRandom $ randomR (0, (length l) - 1)
+                                  r <- d (take i l ++ drop (i + 1) l) (n - 1)
+                                  return (l!!i:r)
+        d _ _ = return []