Data commit

Task/Smith-numbers/Miranda/smith-numbers.miranda

@@ -0,0 +1,28 @@
+main :: [sys_message]
+main = [Stdout (table 5 16 taskOutput),
+        Stdout ("Found " ++ show (#taskOutput) ++ " Smith numbers.\n")]
+       where taskOutput = takewhile (<= 10000) smiths
+
+table :: num->num->[num]->[char]
+table cw w ns = lay (map concat (split (map fmt ns)))
+                where split [] = []
+                      split ls = take w ls : split (drop w ls)
+                      fmt n    = reverse (take cw ((reverse (shownum n)) ++ repeat ' '))
+
+smiths :: [num]
+smiths = filter smith [1..]
+
+smith :: num->bool
+smith n = (~ prime) & digsum n = sum (map digsum facs)
+          where facs  = factors n
+                prime = #facs <= 1
+
+digsum :: num->num
+digsum 0 = 0
+digsum n = n mod 10 + digsum (n div 10)
+
+factors :: num->[num]
+factors = f [] 2
+          where f acc d n = acc,                   if d>n
+                          = f (d:acc) d (n div d), if n mod d = 0
+                          = f acc (d+1) n,         otherwise