leetcode.hs

module Main where

import Data.List (find, groupBy, intercalate, nub, sort, sortBy)
import Data.Ord
import Debug.Trace

-- Solution to
-- https://leetcode.com/problems/largest-number/description/
largest :: [Int] -> String
largest =
  intercalate ""
    . concatMap (sortBy (comparing length))
    . groupBy (\a b -> head a == head b)
    . sortBy (comparing Down)
    . map show

-- Solution to
-- https://leetcode.com/problems/substrings-of-size-three-with-distinct-characters/description/
windows :: (Show a) => Int -> [a] -> [[a]]
windows _ [] = []
windows n a
  | n > length a = []
  | otherwise = trace "Hello" stx : windows n (tail a)
  where
    stx = take n a

countGoodSubstrings :: String -> Int
countGoodSubstrings = length . filter (\x -> length x == (length . nub) x) . windows 3

main :: IO ()
main = do
  putStrLn $ largest [10, 2]

Ooops I forgot to remove unnecessary stuff