update

Task/Priority-queue/Haskell/priority-queue-2.hs

@@ -28,17 +28,16 @@ hLength Nil = 0
 hLength h = cnt h
 
 hFromList :: (Ord a) => [a] -> MinHeap a
-hFromList xs = hlist Nil xs where
-	hlist h [] = h
-	hlist h (x:xs) = hlist (hPush x h) xs
+hFromList = foldl (flip hPush) Nil
 
 hToList :: (Ord a) => MinHeap a -> [a]
-hToList Nil = []
-hToList h = x:hToList hh where (x,hh) = hPop h
+hToList = unfoldr f where
+  f Nil = Nothing
+  f h = Just $ hPop h
 
-main = mapM print $ (hToList (hFromList [
+main = mapM_ print $ hToList $ hFromList [
 	(3, "Clear drains"),
 	(4, "Feed cat"),
 	(5, "Make tea"),
 	(1, "Solve RC tasks"),
-	(2, "Tax return")]))
+	(2, "Tax return")]

Task/Priority-queue/Racket/priority-queue-1.rkt

@@ -0,0 +1,24 @@
+#lang racket
+(require data/heap)
+
+(define pq (make-heap (λ(x y) (<= (second x) (second y)))))
+
+(define (insert! x pri)
+  (heap-add! pq (list pri x)))
+
+(define (remove-min!)
+  (begin0
+    (first (heap-min pq))
+    (heap-remove-min! pq)))
+
+(insert! 3 "Clear drains")
+(insert! 4 "Feed cat")
+(insert! 5 "Make tea")
+(insert! 1 "Solve RC tasks")
+(insert! 2 "Tax return")
+
+(remove-min!)
+(remove-min!)
+(remove-min!)
+(remove-min!)
+(remove-min!)

Task/Priority-queue/Racket/priority-queue-2.rkt

@@ -0,0 +1,5 @@
+"Solve RC tasks"
+"Tax return"
+"Clear drains"
+"Feed cat"
+"Make tea"