diff options
Diffstat (limited to 'challenge-301/ulrich-rieke/haskell/ch-2.hs')
| -rwxr-xr-x | challenge-301/ulrich-rieke/haskell/ch-2.hs | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/challenge-301/ulrich-rieke/haskell/ch-2.hs b/challenge-301/ulrich-rieke/haskell/ch-2.hs new file mode 100755 index 0000000000..03cfa6238d --- /dev/null +++ b/challenge-301/ulrich-rieke/haskell/ch-2.hs @@ -0,0 +1,27 @@ +module Challenge301_2
+ where
+import Data.Bits
+import qualified Data.Set as S
+
+combinations :: Int -> [a] -> [[a]]
+combinations 0 _ = [[]]
+combinations n xs = [ xs !! i : x | i <- [0..(length xs ) - 1 ] ,
+ x <- combinations (n - 1 ) ( drop ( i + 1 ) xs ) ]
+
+hamming_distance :: Int -> Int -> Int
+hamming_distance first second =
+ let orred = first .|. second
+ anded = first .&. second
+ in popCount orred - popCount anded
+
+solution :: [Int] -> Int
+solution list =
+ let allCombis = S.toList $ S.fromList $ combinations 2 list
+ in sum $ map (\subli -> hamming_distance ( head subli ) ( last subli ) )
+ allCombis
+
+main :: IO ( )
+main = do
+ putStrLn "Enter some integers separated by whitespace!"
+ numberline <- getLine
+ print $ solution $ map read $ words numberline
|