2015 ACM-ICPC North America Qualification Contest

This page was last updated October 05, 2015 at 10:05 (America/Chicago).

Contest results

Here is the problem set and here are the Judge's data.

We had 1221 teams register on ICPC registration, but 254 of these had no contestants added, so we effectively had 967 teams that could show up.

We had 977 users on 702 teams sign in, and there were 642 teams that submitted something. Of those, 609 teams (or 94.8% of teams submitting) solved at least one problem. There were 6733 total submissions, or an average of 22.4 per minute for 5 hours.

Here's a table of how many teams solved how many problems:

Problems solved 0 1 2 3 4 5 6 7 8 9 10 11
Number of teams 364 36 66 158 86 84 50 40 23 16 23 27
Recall that some teams were individuals, others had multiple members, so it is not reasonable to compare the performance of teams having different numbers of members.

Here are stats on the problems:

Solved / Tries 262/793 (33%) 264/641 (41%) 78/162 (48%) 101/385 (26%) 50/141 (35%) 565/973 (58%) 116/441 (26%) 503/872 (57%) 597/942 (63%) 228/626 (36%) 77/197 (39%)
Average tries 2.35 1.87 1.53 2.21 1.83 1.66 1.95 1.62 1.54 2.26 1.86
Averages tries to solve 1.95 1.63 1.38 1.92 1.48 1.58 1.60 1.46 1.46 2.07 1.39

Here's the distribution of the delay in judging responses from Kattis:

Maximum delay (seconds): 10 20 30 40 50 60 70
# of submissions: 5639 1040 185 33 13 6 1

Here is the rate of submissions over 10-minute intervals during the contest:
Rate of submissions during the contest


This contest went extremely smoothly overall. Many thanks go to the following people:

Key information for the contest

Kattis accounts and Kattis teams created — We pulled the latest data from ICPC registration and created the Kattis accounts and teams for the contest. Please login to https://naq15.kattis.com/ for the contest using the same contestant email address that is in the ICPC registration system. At this point no modifications to the ICPC registration system data will make it into the contest; you will need to contact contest directors for such help (and it may not be possible to accommodate all requests).

The fourth ACM-ICPC North America Qualification Contest will be October 3, 2015 at 11:00 - 16:00 (CDT). The contest will be held online (on Kattis). If you are a coach, please register your teams (see below). If you are a team member, please communicate with your coach to get your team registered.

The North America Qualifier is an online (distributed) programming contest, offered as a drop-in replacement for so-called "qualifying" contests (e.g. school-level, pre-regional competitions).

Registration (CLOSED)

Registration is now closed. If you (as a coach) have registered teams on icpc.baylor.edu for the North America Qualifier, then you are done. If you have missed registration, we apologize but no additional teams may be registered at this point due to time constraints. However, you can and should populate all your teams with the participants who will be on the teams, so that we may create their Kattis teams.

Each year we have had people register for the incorrect contest, and that has prevented people from participating. Please ensure you have registered for the contest titled "North America Qualifier". Follow the instructions and links below.

There is one contest, with 12 "sites". The 12 sites correspond to the 11 regions of North America, plus one extra site for contestants who are not eligible to compete in ICPC in North America (e.g. high school students or people whose school is not in an ICPC North America region). Please register for the site that corresponds to your region. Here are direct links for each region (using these is likely the simplest route to registration):

You may register as many teams as you like (each team can have anywhere from 1 to 10 competitors — that's up to you). If you are in doubt about how many you may need, register more up front (as it will be impossible to add teams after registration freezes). But please try to be somewhat realistic for our planning purposes.

After registration is closed, due to the number of teams and the limited support it will be impossible to accommodate new registrations or changes to existing registrations. So please register early, make sure you are registered correctly and for the correct contest and site. Note that you should register for the contest called "North America Qualifier". There are other contests with the word "Qualifier" in the name, so be careful. Registering for your regional contest does not register you for this contest.

Once registration is closed, you will receive information on how to access the contest control system (Kattis) via email to the registered coach of each team.

Basic details

Contest scoring

This contest scoring system will be the same as the world finals. That is, the winner is the team solving the most problems. If two teams solve the same number of problems, then the team with the lowest time is the winner. If two teams have the same time the submission time of the last solved problem is used as a tie-breaker.

The time is the sum of the time of submission (in minutes) of the earliest correct submission for each solved problem, plus any penalty minutes for each incorrect submission of a problem prior to solving that problem. Penalties are 20 minutes for any of the following reasons:

Compile error does not incur a penalty; it is not considered a valid submission. Illegal Function does not incur a penalty, but any illegal function will be investigated and a team may be disqualified from the competition if the judges consider the program an attempt to exploit the contest system.

For more information on how Kattis scores problems, please see Kattis documentation.

For problem-writers

We are using the Kattis Problem format for developing problems. This is the format used for the ICPC world finals. It provides a structure for problem writeups, test data, solutions, and configuration. It automates problem verification (for solutions and anti-solutions), time limit determination, and finally installation. There are two parts: the problem format and the problem tools.

Kattis problem format

Here is some information on the Kattis problem format:

Kattis problem tools

After you're done writing your problem, you can use the Kattis problemtools software on a Linux machine to verify the problem (using "verifyproblem") or to compile a PDF or HTML version of your problem statement (using problem2pdf or problem2html, respectively). You can get the Kattis problemtools in two ways:

Primary contact: Greg Hamerly