Andy Georges wrote:
Hi Kaoru,
I have been working through the exercises in Thompson's The Craft of Functional Programming 2nd Ed book. I am looking for a solution web site for Thompson's book. Or maybe the people here can help.
In exercise 4.4, I am asked to define a function
howManyOfFourEqual :: Int -> Int -> Int -> Int -> Int
which returns the number of integers that are equal to each other. For example,
howManyOfFourEqual 1 1 1 1 = 4 howManyOfFourEqual 1 2 3 1 = 2 howManyOfFourEqual 1 2 3 4 = 0
A solution which is applicable to any number of arguments is this:
when this example occurs in the text the new Haskell coder has not been introduced to most of what you suggest. Some of the exercises I felt were meant to be a little painful so that when you were introduced to a new concept a chapter or two later you would think "oh, that would have made X.Y so much easier".