MaxSumOfSubArrOfArrayNums.hs

maxSum' :: [Int] -> Int -> Int -> Int 
maxSum' [] maxEnd maxSofar = maxSofar
maxSum' (x:xs) maxEnd maxSofar = 
  maxSum' xs  maxEnd' (max maxSofar maxEnd')
  where maxEnd' = max (maxEnd + x) 0
        
maxSum :: [Int] -> Int        
maxSum arr = maxSum' arr 0 0