Write a function that has the following property: f(f(x)) = -x for any numeric array x.
Note that there is no restriction on the output for f(x). How bizarre can you make it?
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Problem Comments
Solution Comments
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1 Comment
Andrew Newell
on 9 Dec 2014
This one really surprised me.
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1 Comment
Andrew Newell
on 15 Aug 2013
Getting a little silly!
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