Transcript Combinatorics: Putting the Q in QS First, what's up with this?

Combinatorics: Putting the Q in QS

First, what's up with this?


Second what's the significance of the URL?




http://timesofindia.indiatimes.com/topic/Owen-Astrachan/videos
http://www.youtube.com/watch?v=avkjb9F640k
How many URLs in the same pattern?
What's needed to answer this question?
Why is this funny, or is it?

http://www.youtube.com/watch?v=5ceaqtWhdnI&feature=related
Compsci 82, Fall 2011
7.1
Starting from first principles

Two letter URLs. AA, AB, AC, …, ZX, ZY,ZZ


all upper case letters, how many total?
26 starting with 'A', 26 starting with 'B', …
• What's the total?

Suppose upper and lower case? 52 start with 'A'
• What's the total

What happens if we have three letter URLs?


How many start with 'A'? What's the total?
We have an N-letter URL where each
character takes on one of V values?
Compsci 82, Fall 2011
7.2
Question interlude

See questions from 2010 final


See questions from 2009 final


How do you answer the Qish questions?
What about the first questions on this exam?
How is source code "turned into" a program?

Question picker code from ola's home page
Compsci 82, Fall 2011
7.3
Audio and Video Fingerprint: ContentID

Why does YouTube do this?




http://www.youtube.com/t/contentid
http://www.csh.rit.edu/~parallax/
What is EFF?
https://www.eff.org/deeplinks/2010/03/youtubescontent-id-c-ensorship-problem
Patent 7,917,645
Compsci 82, Fall 2011
7.4
What is in a patent?

Review: what does a patent protect?



Useful, novel, non-obvious "inventions"
How long does patent last? What is provided?
Patents have claims (explanations/diagrams)



Courts can rule a patent invalid, e.g., prior art
When sued a defendant claims non-infringement
Invalidity and non-infringement part of defense
Compsci 82, Fall 2011
7.5
In the news: http://bloom.bg/nBPV5s
“From our perspective, we will end up having
enough patents that we can end up with a
rough truce with everybody else, which is
how it’s done,” Schmidt said of Google’s plan
to “bulk up” on patents. “That’s been the
pattern in all other industries, and I’d expect
something similar in ours.
http://bit.ly/pzFyI6
Compsci 82, Fall 2011
7.6
Open Source in the News

http://bit.ly/pzFyI6


What is MeeGo, http://bit.ly/pn6TwK


Why is health care a big issue and big business?
Why the "fear" of Android?
Why audit code? http://bit.ly/o0ccIc

Why not for proprietary code?
Compsci 82, Fall 2011
7.7
What is the IGF? http://huff.to/mSfNka
The Internet Governance Forum doesn't have
any power, but it does have influence because
it brings together people from around the
world who help set the agenda for further
discussions and, possibly, regulations. Its
origins date back to the 2005 meeting of the
World Summit on the Information Society.
Unlike most U.N. bodies, IGF consists not just
of government representatives, but people
from industry and nonprofit organizations.
Compsci 82, Fall 2011
7.8