finish day four

four-easy.hs

@@ -0,0 +1,31 @@
+import           Control.Monad
+import           Data.Char
+
+parseLine :: String -> [[Int]]
+parseLine line = [parseAssignment $ takeWhile (/= ',') line,
+  parseAssignment $ drop 1 $ dropWhile (',' /= ) line]
+
+parseAssignment :: String -> [Int]
+parseAssignment assignment = do
+  let first = takeWhile ('-' /=) assignment
+  let second = drop 1 $  dropWhile ('-' /=) assignment
+  [(read first)..  (read second)]
+
+isIncludedElseWhere ::  [[Int]] -> [Int] -> [[Int]] -> Int -> Int
+isIncludedElseWhere previous current [] count=count
+isIncludedElseWhere previous current next count=do
+  let found = (isIncluded current previous && isIncluded current next)
+  (if found then 1 else 0) +
+    (isIncludedElseWhere (current:previous) (head next) (tail next) count)
+
+isIncluded :: [Int] -> [[Int]] -> Bool
+isIncluded current list = any includes list
+  where
+    includes :: [Int] -> Bool
+    includes range' = all (`elem` range') current
+
+
+main = do
+  input <- readFile "four-input2.txt"
+  let lists= ( join $ map (parseLine) $ lines input)
+  print $ isIncludedElseWhere [] (head lists) (tail lists) 0

four.hs

@@ -0,0 +1,28 @@
+import           Control.Monad
+import           Data.Char
+
+parseLine :: String -> [[Int]]
+parseLine line = [parseAssignment $ takeWhile (/= ',') line,
+  parseAssignment $ drop 1 $ dropWhile (',' /= ) line]
+
+parseAssignment :: String -> [Int]
+parseAssignment assignment = do
+  let first = takeWhile ('-' /=) assignment
+  let second = drop 1 $  dropWhile ('-' /=) assignment
+  [(read first)..  (read second)]
+
+
+isIncluded :: [Int] -> [[Int]] -> Bool
+isIncluded current list = any includes list
+  where
+    includes :: [Int] -> Bool
+    includes range' = all (`elem` range') current
+
+coveredByPartner :: [[Int]] -> Bool
+coveredByPartner [first,second] = isIncluded first [second] ||  isIncluded second [first]
+
+
+main = do
+  input <- readFile "four-input.txt"
+  let lists= (map (parseLine) $ lines input)
+  print $ length $  filter id $  map coveredByPartner lists

four2.hs

@@ -0,0 +1,25 @@
+import           Control.Monad
+import           Data.Char
+import           Data.List
+
+parseLine :: String -> [[Int]]
+parseLine line = [parseAssignment $ takeWhile (/= ',') line,
+  parseAssignment $ drop 1 $ dropWhile (',' /= ) line]
+
+parseAssignment :: String -> [Int]
+parseAssignment assignment = do
+  let first = takeWhile ('-' /=) assignment
+  let second = drop 1 $  dropWhile ('-' /=) assignment
+  [(read first)..  (read second)]
+
+
+
+
+coveredByPartner :: [[Int]] -> Bool
+coveredByPartner [first,second] = 0 /= (length $ intersect first second)
+
+
+main = do
+  input <- readFile "four-input.txt"
+  let lists= (map (parseLine) $ lines input)
+  print $ length $  filter id $  map coveredByPartner lists