Question

Oz programming

Write two functions which compute the sum of squares of the integers stored in a list. for example, if the input is [1 ~2 3 ~4], the output should be 30. which of the implementation is better (foldR or foldL) in terms of size of the semantic stack?

Answer 1

Solution: Here is your answer hope this helps you.

Consider calculating the sum of the squares of the numbers 1 to n. Now calculate
two intermediate lists, one of which is the list 1 to n, and the second is the
squares of 1 to n

we know in haskell how to write the code:
sumSquare :: Int -> Int
sumSquare n = sum (map square [1..n])
square :: Int -> Int
square x = x * x

It is also possible to write a function that computes the sum of the squares of
the numbers 1 to n without using any intermediate lists. For example:
sumSquare :: Int -> Int
sumSquare n = sumSq' 1
where
sumSquare' x = if x > n
then 0
else square x + sumSquare' (x+1)
So you know the effcient the program is arguably less modular and harder to
understand specifically because the program no longer expresses the natural
pipeline structure of this calculation