Initial data commit

Task/Padovan-sequence/Haskell/padovan-sequence-1.hs

@@ -0,0 +1,41 @@
+-- list of Padovan numbers using recurrence
+pRec = map (\(a,_,_) -> a) $ iterate (\(a,b,c) -> (b,c,a+b)) (1,1,1)
+
+-- list of Padovan numbers using self-referential lazy lists
+pSelfRef = 1 : 1 : 1 : zipWith (+) pSelfRef (tail pSelfRef)
+
+-- list of Padovan numbers generated from floor function
+pFloor = map f [0..]
+    where f n = floor $ p**fromInteger (pred n) / s + 0.5
+          p   = 1.324717957244746025960908854
+          s   = 1.0453567932525329623
+
+-- list of L-system strings
+lSystem = iterate f "A"
+    where f []      = []
+          f ('A':s) = 'B':f s
+          f ('B':s) = 'C':f s
+          f ('C':s) = 'A':'B':f s
+
+-- check if first N elements match
+checkN n as bs = take n as == take n bs
+
+main = do
+    putStr "P_0 .. P_19: "
+    putStrLn $ unwords $ map show $ take 20 pRec
+
+    putStr "The floor- and recurrence-based functions "
+    putStr $ if checkN 64 pRec pFloor then "match" else "do not match"
+    putStr " from P_0 to P_63.\n"
+
+    putStr "The self-referential- and recurrence-based functions "
+    putStr $ if checkN 64 pRec pSelfRef then "match" else "do not match"
+    putStr " from P_0 to P_63.\n\n"
+
+    putStr "The first 10 L-system strings are:\n"
+    putStrLn $ unwords $ take 10 lSystem
+
+    putStr "\nThe floor- and L-system-based functions "
+    putStr $ if checkN 32 pFloor (map length lSystem)
+             then "match" else "do not match"
+    putStr " from P_0 to P_31.\n"