Data commit

Task/Happy-numbers/Miranda/happy-numbers.miranda

@@ -0,0 +1,22 @@
+main :: [sys_message]
+main = [Stdout (lay (map show (take 8 happynumbers)))]
+
+happynumbers :: [num]
+happynumbers = filter ishappy [1..]
+
+ishappy :: num->bool
+ishappy n = 1 $in loop (iterate sumdigitsquares n)
+
+sumdigitsquares :: num->num
+sumdigitsquares 0 = 0
+sumdigitsquares n = (n mod 10)^2 + sumdigitsquares (n div 10)
+
+loop :: [*]->[*]
+loop = loop' []
+       where loop' mem (a:as) = mem,              if a $in mem
+                              = loop' (a:mem) as, otherwise
+
+in :: *->[*]->bool
+in val []     = False
+in val (a:as) = True,       if a=val
+              = val $in as, otherwise