1 files changed, 12 insertions, 0 deletions
diff --git a/80-89/81.hs b/80-89/81.hs
new file mode 100644
index 0000000..9bf42d8
--- /dev/null
+++ b/80-89/81.hs
@@ -0,0 +1,12 @@
+import Data.List (partition)
+
+paths :: Eq a => a -> a -> [(a, a)] -> [[a]]
+
+paths s t edges = map reverse $ paths' s edges [s]
+    where
+        paths' u edges path
+            | u == t = [path]
+            | otherwise =
+                do  let (vs, edges') = partition ((== u) . fst) edges
+                    (_, v) <- vs
+                    paths' v edges' (v:path)