day7. finally.

Makefile

@@ -1,4 +1,4 @@
-DAY = 10
+DAY = 7
 
 DIR = day$(DAY)
 

day7/main.hs

@@ -0,0 +1,122 @@
+import System.IO
+
+import Data.List
+import Data.List.Split
+
+import Debug.Trace
+
+
+
+data Node = File String Int | Dir String Int [Node] deriving (Show)
+
+instance Eq Node where
+    Dir n1 _ _ == Dir n2 _ _ = n1 == n2
+    File n1 _  == File n2 _  = n1 == n2
+
+instance Ord Node where
+    Dir _ s1 _ `compare` Dir _ s2 _ = s1 `compare` s2
+    File _ s1  `compare` File _ s2  = s1 `compare` s2
+
+nodeSize :: Node -> Int
+nodeSize (File _ s) = s
+nodeSize (Dir _ s _) = s
+
+
+nodeInfo :: Node -> String
+nodeInfo (File n s) = n ++ "(file, size=" ++ show s ++ ")"
+nodeInfo (Dir n s _) = n ++ "(dir, size=" ++ show s ++ ")"
+
+printNode :: Int -> Node -> String
+printNode lvl n = case n of
+    File n s  -> sp ++ "- " ++ n ++ " (file, size=" ++ show s ++ ")\n"
+    Dir n s c -> sp ++ "- " ++ n ++ " (dir, size=" ++ show s ++ ")\n" ++ printNodes (lvl+1) c
+    where
+        sp = replicate (2*lvl) ' '
+
+printNodes :: Int -> [Node] -> String
+printNodes a = concat . map (printNode a)
+
+
+
+
+
+--parseDir' :: [String] -> [Node]
+--parseDir' (x:xs) =
+
+dirInNodes :: String -> [Node] -> (Bool,Node,[Node])
+dirInNodes name onodes = (exists, instanc, removed)
+    where
+        matches = filter (\node@(Dir n _ _) -> n == name) onodes
+        exists  = (length matches) > 0
+        instanc = if exists then head matches else File "<nonexistent>" 0
+        removed = delete instanc onodes
+
+
+
+
+parseDir :: [Node] -> [Node] -> [String] -> ([Node],[String])
+parseDir onodes nodes (x:xs)
+    | "$ cd " `isPrefixOf` x = ((Dir (drop 5 x) (sum $ map nodeSize nodes) nodes:onodes), xs)
+    | "dir "  `isPrefixOf` x = case dirInNodes (drop 4 x) onodes of
+                                    (True,node,restnodes) -> parseDir restnodes (node:nodes) xs
+                                    (False,_,_) -> parseDir onodes nodes xs
+    | otherwise = parseDir onodes (File fname fsize:nodes) xs
+    where
+        [fsize',fname] = splitOn " " x
+        fsize = read fsize' :: Int
+
+
+
+parseCli :: [Node] ->  [String] -> [String] -> [Node]
+parseCli nodes [] [] = []
+parseCli nodes stack [] = onodes ++ parseCli onodes reststack []
+    where (onodes,reststack) = parseDir nodes [] $ stack
+parseCli nodes stack (x:xs)
+    | x == "$ cd .." = onodes ++ parseCli onodes reststack xs
+    | otherwise = parseCli nodes (x:stack) xs
+    where (onodes,reststack) = parseDir nodes [] $ stack
+
+
+prepCli :: [String] -> [String]
+prepCli = filter (/= "$ ls")
+
+
+
+
+
+findNodes :: (Node -> Bool) -> Node -> [Node]
+findNodes f file@(File _ _) = if (f file) then [file] else []
+findNodes f dir@(Dir _ _ c) = (if (f dir) then [dir] else []) ++ (concat $ map (findNodes f) c)
+
+
+dirSize :: (Int -> Bool) -> Node -> Bool
+dirSize _ (File _ _)  = False
+dirSize f (Dir _ s _) = f s
+
+
+
+
+findDeletable :: Int -> Int -> Node -> Node
+findDeletable fss req root@(Dir _ used _) = smallest
+    where
+        tbf = req - (fss-used)
+        candidates = findNodes (dirSize (>= tbf)) root
+        smallest = head $ sort candidates
+
+
+
+
+handler :: String -> String
+handler s = (show sumUnder) ++ "\n" ++
+            (show savsize) ++ "\n"
+    where
+        rootNode = last $ parseCli [] [] $ prepCli $ lines s
+        under100k = findNodes (dirSize (<= 100000)) rootNode
+        sumUnder = sum $ map (\(Dir _ s _) -> s) under100k
+        (Dir _ savsize _) = findDeletable 70000000 30000000 rootNode
+
+main :: IO ()
+main = do
+    interact handler
+
+