All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Logic
Triple Negative (Posted on 2004-02-12) Difficulty: 4 of 5
Using only two inverters and an unlimited number of AND and OR gates in a logic circuit, show how to invert an arbitrary number of inputs.

(For instance, if you have four inputs, the circuit will have four outputs that are the inverses of the four inputs)

No Solution Yet Submitted by DJ    
Rating: 4.1250 (8 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution So... | Comment 14 of 19 |
(In reply to Of course you could do this by Charlie)

I don't think you actually can invert an arbitrary number of inputs with just 2 inverters. I think the original quote from the internet is correct: with n inverters you can do 2^n - 1 inversions. Put another way, to do i inversions, you need n = ceil(log(i+1)) inverters, using base-2 logarithms.
  Posted by Charlie on 2004-02-14 11:19:13

Please log in:
Remember me:
Sign up! | Forgot password

Search body:
Forums (2)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (10)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2020 by Animus Pactum Consulting. All rights reserved. Privacy Information