Archive for the ‘2011 Regionals’ Category

Here is a video of a webcast of the Chief Judge (me) discussing each of the problems in the 2011 problem set. The original lecture was given at Georgia Tech on Thursday, 11 November. The video is about 90 minutes long. The real content starts at about the 2 minute mark.

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Problem Approximate time it starts
Sunday Drive 4:00
Hexagram 9:00
Flooring Tiles 14:30
Vive la Difference! (Proof of 3n convergence) 27:00
Robot Navigation 41:45
Folding Game 49:45
Burnout 52:45
Family Fortune 63:55
Moving Points 73:00
Vampire Numbers 81:35
Sunday, November 20th, 2011 at 08:21 | 0 comments
Categories: 2011 Regionals

In the problem statement for Vive la Difference, we make the claim that if all four numbers are less than 2^n, then it will converge in no more than 3n steps. This PowerPoint presentation outlines a proof.

Wednesday, November 2nd, 2011 at 20:55 | 0 comments
Categories: 2011 Regionals

Here it is – the 2011 problem set. You can download the text from here.

Problem Judge Data Solutions
A: Sunday Drive

Our Rating: C/D
Submissions: 43
Solutions: 14
B: Hexagram

Our Rating: C/D
Submissions: 13
Solutions: 8
C: Flooring Tiles

Our Rating: C/D
Submissions: 35
Solutions: 9
D: Vive la Difference!

Our Rating: A/B
Submissions: 102
Solutions: 78
E: Robot Navigation

Our Rating: C/D
Submissions: 16
Solutions: 7
F: Folding Game

Our Rating: E/F
Submissions: 14
Solutions: 2
G: Burnout

Our Rating: C/D
Submissions: 85
Solutions: 0
H:Family Fortune

Our Rating: E/F
Submissions: 3
Solutions: 0
I: Moving Points

Our Rating: E/F
Submissions: 4
Solutions: 2
J: Vampire Numbers

Our Rating: A/B
Submissions: 86
Solutions: 30

Saturday, October 29th, 2011 at 19:20 | 0 comments
Categories: 2011 Regionals

Here’s the Call for Problems that was recently sent out to all SER coaches and Problem Selection Committee members:

Summer is upon us, World Finals is over, so it’s time to start thinking, just a little bit, about the Southeast USA Regional Programming Contest. It’ll be a little bit earlier this year, on Saturday, 29 October. So, spend your summer dreaming up programming problems! Also, we’re looking for people to serve on the Problem Selection Committee. Putting together the problem set for SER is an intense, rewarding process. If you’re interested, send me an e-mail (at

As usual, the Problem Selection Committee will be responsible for putting the problem set together. The PSC will also be responsible for judging, so problem providers won’t have to judge. Because of this, you can provide a problem, and also coach your team, and attend the contest with them at your chosen site. Anyone can submit a problem for consideration – however, although a problem submitter can also act as a coach, they cannot be a contestant, whether or not their problem is chosen for the set. In other words, if a student submits a problem, they are ineligible to compete.

Candidate problems should be e-mailed to me (at A statement of the problem is all that’s necessary, either in text or in MS Word format (right in the e-mail is fine). If you wish to include a solving program and/or test data, that’s very, very helpful, but not necessary. If you have a rough idea and want to talk about it, feel free to e-mail it to me, and I’ll be happy to work with you.

Problems should be sent by Friday, 9 September to be eligible for consideration. That’s the Friday after Labor Day. I’ll remind you again, but I’m sending out the call for problems early, to get you thinking!

Below you will find an excerpt from the Call for Problems issued from World Finals this year. It’s a good set of guidelines for candidate problems. If you are thinking of submitting a candidate problem for Southeast Regionals, you should read through it. I will add a couple of constraints of my own:

  1. The problem should be original. It should not be a restatement of a problem that has been used previously in the Southeast USA, or any other ICPC regional, World Finals, or other contest environment such as TopCoder or Google CodeJam. It also should not come from a book, such as “Programming Challenges.” If it has its own Wikipedia page, then it’s too well-known.
  2. The output for any given input should be unique. Try to add constraints to your problem so that there is exactly one answer for each input case.

Don’t forget about the blog to talk about judging at our contest. It’s at:

Feel free to drop by and give suggestions – however, do NOT post candidate problems on this site. It is open to everyone, including students. Any problem posted on the site cannot be used in the contest.

————- Some excerpts from the World Finals call for problems: ————-

Problem Statements

  1. Each problem must be unambiguously described in English.
  2. All problems must require input.
  3. Unless the core of the problem is input/output related, the formats chosen for input data and the displayed results should be relatively simple. Still, the format of the input data and the appearance of the expected displayed results must be described in suitable detail.
  4. Multiple data sets testing different cases are appropriate; make the problem statement include iterative data sets as input to avoid using separate input files.
  5. Anticipate questions about special cases. Where appropriate, explicitly state that certain special cases will not appear in the input data. It is not necessary to specifically identify the special cases that will appear.
  6. Indicate the precision that is required for real results.
  7. Contestants must write solutions for problems in a short time. While very simple problems are not appropriate, neither are problems that require a great deal of code; a few hundred lines of Java or C should be an upper limit on what can be expected in a solution.
  8. The program and chosen test data should not require excessive execution time. Contestants’ solutions may be less efficient than yours and so a generous margin is allowed for execution. If your test data requires the program to execute for a long time, then incorrect student solutions (e.g., those with infinite loops) will take an excessively long time to judge. We would like to avoid those situations.
  9. The problem description (excluding sample input/output) should generally require at most one page.

Submission of Problems, Solutions, and Test Data

  1. Use electronic mail and send all files as either MS Word document, or flat ASCII.
  2. Do not put your name in documents, or the body of e-mails, containing the problem statement, solution, or test data. This will simplify the transformation from your form to the one used for ranking.
  3. Be discreet about problem statements and solutions. It is not appropriate to discuss problems with people not involved with the contest.
Saturday, June 25th, 2011 at 09:14 | 0 comments
Categories: 2011 Regionals