Day 7 Part 2

src/Day7.hs

@@ -81,7 +81,6 @@ filterDirectories predicate dir = filter (\(_, size) -> predicate size) $ sizeOf
 sumUp :: [(String, Int)] -> Int
 sumUp = sum . map snd
 
-
 forceRight :: Either a b -> b
 forceRight (Left _) = error "forced Right but got Left"
 forceRight (Right b) = b
@@ -92,6 +91,16 @@ day7 = do
    putStrLn "Day7"
    let parsed = forceRight $ parseTerminalLines input
    let tree = buildTree parsed
-   let filtered = filterDirectories (<= 100000) tree
-   let summed = sumUp filtered
-   putStrLn ("Sum of those directories is " ++ show summed)
+   let small = filterDirectories (<= 100000) tree
+   let sumOfSmall = sumUp small
+   putStrLn ("Sum of those directories is " ++ show sumOfSmall)
+   let rootSize = snd . head $ sizeOfDirectories tree
+   putStrLn ("Root size is " ++ show rootSize)
+   let freeSpace = 70000000 - rootSize
+   let requiredSpace = 30000000 - freeSpace
+   putStrLn ("Required space is " ++ show requiredSpace)
+   let bigEnough = filterDirectories (>= requiredSpace) tree
+   let onlySizes = map snd bigEnough
+   let smallest = minimum onlySizes
+   putStrLn ("Smallest directory that is still large enough " ++ show smallest)
+