Problem 6: Sums of Squares of Sums

14 10 2009

Difference between sum of squares and square of sums

Find the difference between the sum of squares and the square of the sum of the integers 1 to 100

Using the functions map and reduce, this becomes trivial to implement

(defn sqr [x]
    (* x x))

(let [terms (range 1 101)]
    (- (reduce + (map sqr terms)) (sqr (reduce + terms))))

map takes a function and 1 or more lists and generates a new list of terms which are a result of the application of the function on each of the terms in the list/lists

(map + '(1 2 3) '(1 2 3))
=> (2 4 6)



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: