Your first contest

You will run a 60-minute class contest with 2–3 existing problems, open only to your class, then review the ranking and download the data afterwards.

⏱ ~25 min setup (+60 min contest) · 👤 Teachers, contest organizers · 🔑 judge.add_contest, or organization admin with judge.create_private_contest; adding testers needs a staff account

What you'll do

• Create the contest in the web UI: key, name, start and end time, format.
• Add 2–3 problems and set their points.
• Restrict entry: private to an organization (class) or protected by an access code.
• Try the contest with a tester account before it starts.
• After it ends: view the ranking, open virtual participation, download submissions.

Before you start

• You have 2–3 problems with tests that already pass an AC test submission (see Your first problem). Keep them private: anyone can read a public problem without joining the contest.
• You have one of:
  • judge.add_contest: you see the Add new contest tab on /contests/; or
  • you are an organization admin (of the class) with judge.create_private_contest: you see the Create new contest tab on the organization page.
• You have judge.edit_own_contest so you can edit the contest after creating it.
• For a class-only contest: the class organization exists and students have joined it (see Organizations).
• A second account to act as tester, and someone with a staff account (possibly you) to add the tester in the admin.

See Permissions to ask an administrator for these.

Step 1: Create the contest

Goal: a 60-minute contest with the right key, schedule, and format.

1. Open the contest creation page one of two ways:

   Way	Where	Notes
   Inside an organization (recommended for classes)	/organization/<slug> → Create new contest tab	The contest is automatically private to the organization. The key must start with the organization prefix (pre-filled, e.g. class10a_)
   General contest	/contests/ → Add new contest tab (URL /contests/new)	A normal contest; restrict entry with an access code or in the admin

2. Fill in the form:

   Field	Example	Notes
   Contest id	class10a_quiz1	Lowercase letters, digits, and _ only (^[a-z0-9_]+$), at most 32 characters, unique. Used in the URL /contest/<key>
   Contest name	Quiz 1 - Class 10A	At most 100 characters
   Start time	2026-10-05 14:00:00	In your account's time zone
   End time	2026-10-05 15:00:00	At most 14 days after the start
   Publicly visible	✅ checked	Required for students to see the contest, even an organization-private one
   Scoreboard visibility	Visible	Pick Hidden for duration of contest if students should not see standings during the contest
   Contest format	IOI (ioi16) or ICPC	See the table below
   Description	Rules, allowed languages…	Markdown

   Leave the other fields (No comments, Hide problem tags, Hide problem authors, Show short form settings display) at their defaults. Access code and Private to specific users are covered in Step 3.

Picking a format: IOI or ICPC?

	IOI (ioi16)	ICPC (icpc)
Points per problem	Sum of the best score of each subtask across all submissions	Best score of a single submission
Wrong submissions	No penalty	20-minute penalty per wrong submission before reaching the best score
Ties	Tied rank (default)	Lower total time + penalty ranks higher
Scoreboard freeze	No	Yes (set in the admin)
Problem labels	1, 2, 3	A, B, C
Good for	Problems with subtasks, partial scoring, class tests	Team contests, speed practice; usually 1 point per problem

ioi16 scores by batch. If your problems have no subtasks, choose IOI (pre-2016) (ioi) or Default (default) instead. Details: Contest formats.

✅ Result: the information part of the form is filled in; do not click Create yet (you add problems in the next step, on the same form).

Step 2: Add problems and points

Goal: the contest has 3 problems with the right points and order.

1. Scroll to the Problems section. The table has the columns Problems, Points, Order in contest, Max submission, and Delete.
2. In the first row, click the problem picker, type a code or name (e.g. aplusb), and select it. You can only pick problems you can see. For an organization contest, the picker has two tabs: Organization problems and Public problems.
3. Enter Points (an integer), e.g. 100. For classic ICPC, use 1 per problem.
4. Enter Order in contest 1, 2, 3 (no duplicates). Or click Switch to drag and drop mode to reorder with the mouse; the order is numbered automatically.
5. (Optional) Max submission: maximum submissions per problem; leave blank for no limit.
6. Click add another below the table if you need more rows.
7. Click Create.

✅ Result: you land on the contest page /contest/class10a_quiz1. You are its author automatically and see the Info, Statistics, and Edit tabs. To change problems or times later, click Edit (/contest/<key>/edit), make changes, and click Update.

Step 3: Restrict entry

Goal: only your class can get in. Pick one approach:

Approach	How	What students see
A. Private to an organization	If you created it from the organization page (Step 1), you are done. If you used /contests/new: in the admin (Step 4), under Access, tick Private to organizations and choose the Organization (needs judge.create_private_contest)	Only organization members see the contest in the list
B. Access code	In Edit, fill in Access code, e.g. 10a-monday, then Update. Read the code to the class when the contest starts	Everyone who can see the contest must enter the code: Join contest → Please enter your access code: → Join Contest
C. List of contestants	In Edit, tick Private to specific users, then add usernames under Private contestants (paste a whole list and press Enter)	Only listed users see the contest

You can combine A and B: only class members see the contest, and they still need the code to get in.

✅ Result: the contest page (Info tab) reflects your setup; with an access code, the rules summary says an access code is required (when Show short form settings display is on).

Step 4: Add a tester and advanced settings (admin)

Goal: a tester account can open the contest before it starts.

The site form has no tester field. This is done in the admin with a staff account that has judge.edit_own_contest (or ask an administrator):

1. Open the contest's Edit page and click Edit contest in admin panel for more options (only shown to staff). Or open /admin/judge/contest/ and pick the contest.

2. In Testers (top of the page), add the tester account.

3. (Optional, same page) admin-only settings:

   Field	When to use it
   Frozen last minutes (Format section)	ICPC/VNOJ only, e.g. 15 to freeze the scoreboard for the last 15 minutes. After the contest, set it back to 0 to reveal the real standings
   Contest format configuration	JSON options for the format, e.g. {"penalty": 10} for ICPC
   Time limit (Scheduling section)	Each contestant gets a personal window (e.g. 60 minutes) starting when they join, inside the start–end range. Leave blank for a fixed-time contest like this one
   Disallow virtual joining (Settings section)	Tick it if nobody should do the contest virtually after it ends
   Partial column in the problems table	Untick so a problem only scores when fully solved (ICPC style)

4. Click Save.

✅ Result: the tester account can open /contest/<key> even though the contest has not started.

Step 5: Try the contest as the tester

Goal: make sure statements display correctly and submissions get judged.

1. Sign in as the tester (use a private window or another browser).
2. Open /contest/<key> and click Spectate contest. Testers and authors always enter as spectators, even before the start.
3. Open each problem in the contest's problem list, read it, and submit a correct solution.
4. Click Leave contest when done.

✅ Result: the submissions are judged AC. Spectators do not appear on the ranking, so testing does not affect the real results.

Check the student view

Sign in as an ordinary student account (not a tester) and open /contests/: the contest should appear in the list with a countdown. If it does not, recheck Publicly visible and the restriction from Step 3.

Step 6: Run the contest

Goal: students get in and you can follow along.

1. At the start time, students open /contest/<key> and click Join contest (entering the access code if there is one). Before the start, the button is not shown.
2. Watch the Rankings tab (/contest/<key>/ranking/) and the Submissions tab.
3. At the end time, the contest closes by itself.

✅ Result: the ranking updates after each judged submission (unless you hid the scoreboard or it is frozen).

Step 7: After the contest

Goal: publish results, allow practice, and archive submissions.

1. View the ranking: the Rankings tab. If you used ICPC with a freeze, set Frozen last minutes back to 0 in the admin and click Save to reveal the real standings.
2. Open virtual participation: after the contest ends, anyone who missed it (or wants a retry) sees a Virtual join button on the contest page; each virtual run gets the full 60 minutes. On the ranking, tick Show virtual participations to include virtual runs. If you ticked Disallow virtual joining in Step 4, the button does not appear.
3. Download data: on the contest page, in the Problems section, click Download data. On the Download contest data page, keep Download submissions? checked, click Prepare download, wait for it to finish, then click Download prepared data to get <key>-data.zip. Details: Contest data download.
4. (Optional) To move the problems into the practice archive, click Make All Problems Public on the contest page.

✅ Result: the final ranking is visible, the Virtual join button is on the contest page, and you have a zip of the contestants' submissions.

Verify

• Class members see the contest on /contests/; accounts outside the class (or without the code) cannot get in.
• The tester got in before the start and the tester's submissions were judged.
• Problem labels and scoring on the ranking match the chosen format (1, 2, 3 for IOI; A, B, C for ICPC).
• After the end, Virtual join appears and you can download <key>-data.zip.

Troubleshooting

Symptom	Cause	Fix
No Add new contest / Create new contest tab	Missing judge.add_contest, or not an organization admin / missing judge.create_private_contest	Ask an administrator for the permission
"Contest id must starts with …"	Organization contests need the organization prefix	Keep the pre-filled prefix and append to it
"Only accept alphanumeric characters (a-z, 0-9) and underscore (_)"	The key has uppercase letters, -, or spaces	Fix the key
"Contest duration cannot be longer than 14 days"	The end time is too far out	Shorten the window
"Problems must have distinct order."	Two problems share the same order	Number them 1, 2, 3 or use drag and drop mode
A problem cannot be found when adding	You cannot see that problem	Ask its author to add you as a curator, or pick another problem
Students cannot see the contest	Publicly visible is not ticked, or students are not in the organization / not on the list	Fix per Steps 1 and 3
Students see the contest but no Join contest button	It has not started yet	Wait; double-check the time zone you scheduled in
You (the author) only see Spectate contest	Authors and testers can only spectate, not compete	Working as intended; use a student account to compete
Students could read the problems before the contest	The problems are public	Hide them beforehand (admin action Mark problems as private)
The scoreboard stays frozen after the contest	ICPC/VNOJ keep the freeze after the end	Set Frozen last minutes to 0 in the admin
No Download data button	You cannot edit the contest, or the feature is disabled on the server	See Contest data download
"Please wait until the contest has ended to download data."	The contest has not ended	Wait for the end time and try again

Next steps

• Contest setup: every setting, registration, terms, rating.
• Contest formats: scoring, penalties, and freezing for each format.
• Organizations: create a class and manage members.
• Contest data download: the layout of the submissions zip.
• Taking part in contests: the contestant's view.