Solve 526989a41034285187000de4

Author: tbsklg

src/Kyu5/Bananas.hs

@@ -8,7 +8,6 @@ bananas xs = go xs banana
   where
     go xs [] = ['-' <$ xs]
     go [] _ = []
-    go (x : xs) (b : bs) = 
-      [x : rest | x == b, rest <- go xs bs] 
+    go (x : xs) (b : bs) =
+      [x : rest | x == b, rest <- go xs bs]
         ++ ['-' : rest | rest <- go xs (b : bs)]
-

src/Kyu5/IpsBetween.hs

@@ -0,0 +1,11 @@
+module Kyu5.IpsBetween where
+
+import Data.List.Split (splitOn)
+
+type Ipv4 = String
+
+ipsBetween :: Ipv4 -> Ipv4 -> Int
+ipsBetween from to = to32Bit to - to32Bit from
+
+to32Bit :: Ipv4 -> Int
+to32Bit ip = foldl (\acc x -> acc * 256 + x) 0 $ map read $ splitOn "." ip

test/Kyu5/BananasSpec.hs

@@ -1,21 +1,33 @@
 module Kyu5.BananasSpec (spec) where
 
-import Kyu5.Bananas (bananas)
-import Test.Hspec
 import Control.Monad (when)
 import Data.List (sort)
+import Kyu5.Bananas (bananas)
+import Test.Hspec
 
 spec :: Spec
 spec = do
   describe "Example tests" $ do
     it "example 0" $ test "banann" []
     it "example 1" $ test "banana" ["banana"]
-    it "example 2" $ test "bbananana" ["-b--anana","-ba--nana","-ban--ana","-bana--na"
-                                      ,"-banan--a","-banana--","b---anana","b-a--nana"
-                                      ,"b-an--ana","b-ana--na","b-anan--a","b-anana--"
-                                      ]
-    it "example 3" $ test "bananaaa" ["banan--a","banan-a-","banana--"]
-    it "example 4" $ test "bananana" ["b--anana","ba--nana","ban--ana","bana--na","banan--a","banana--"]
+    it "example 2" $
+      test
+        "bbananana"
+        [ "-b--anana",
+          "-ba--nana",
+          "-ban--ana",
+          "-bana--na",
+          "-banan--a",
+          "-banana--",
+          "b---anana",
+          "b-a--nana",
+          "b-an--ana",
+          "b-ana--na",
+          "b-anan--a",
+          "b-anana--"
+        ]
+    it "example 3" $ test "bananaaa" ["banan--a", "banan-a-", "banana--"]
+    it "example 4" $ test "bananana" ["b--anana", "ba--nana", "ban--ana", "bana--na", "banan--a", "banana--"]
 
 test :: String -> [String] -> Expectation
 test xs expected = do

test/Kyu5/IpsBetweenSpec.hs

@@ -0,0 +1,39 @@
+module Kyu5.IpsBetweenSpec where
+
+import Data.List
+import Data.List.Split
+import Kyu5.IpsBetween
+import Test.Hspec
+import Test.QuickCheck
+
+spec :: Spec
+spec = do
+  describe "ipsBetween" $ do
+    it "basic" $ do
+      ipsBetween "10.0.0.0" "10.0.0.50" `shouldBe` 50
+      ipsBetween "20.0.0.10" "20.0.1.0" `shouldBe` 246
+      ipsBetween "150.0.0.0" "150.0.0.1" `shouldBe` 1
+      ipsBetween "10.0.0.0" "10.0.0.50" `shouldBe` 50
+      ipsBetween "20.0.0.10" "20.0.1.0" `shouldBe` 246
+      ipsBetween "10.11.12.13" "10.11.13.0" `shouldBe` 243
+      ipsBetween "160.0.0.0" "160.0.1.0" `shouldBe` 256
+      ipsBetween "170.0.0.0" "170.1.0.0" `shouldBe` 65536
+      ipsBetween "50.0.0.0" "50.1.1.1" `shouldBe` 65793
+      ipsBetween "180.0.0.0" "181.0.0.0" `shouldBe` 16777216
+      ipsBetween "1.2.3.4" "5.6.7.8" `shouldBe` 67372036
+
+    it "random" $ do
+      forAll (vectorOf 4 (choose (0, 255))) $ \x ->
+        forAll (vectorOf 4 (choose (0, 255))) $ \y ->
+          let from = asIP x
+              to = asIP y
+           in to32Bit' to <= to32Bit' from ==> collect (from, to) $ ipsBetween from to === solution from to
+
+asIP :: [Int] -> String
+asIP = intercalate "." . map show
+
+solution :: String -> String -> Int
+solution from to = to32Bit' to - to32Bit' from
+
+to32Bit' :: String -> Int
+to32Bit' ip = foldl (\acc x -> acc * 256 + x) 0 $ map read $ splitOn "." ip