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?
Solution Stats
Problem Comments
Solution Comments
-
1 Comment
Andrew Newell
on 9 Dec 2014
This one really surprised me.
-
1 Comment
Andrew Newell
on 15 Aug 2013
Getting a little silly!
Recent Solvers56
Suggested Problems
-
Project Euler: Problem 10, Sum of Primes
525 Solvers
-
232 Solvers
-
Getting the row and column location from a matrix
186 Solvers
-
Determine if input is a perfect number
106 Solvers
-
Switch matrix to a column vector
178 Solvers
More from this Author9
Tags
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
Select web siteYou can also select a web site from the following list:
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)