Internet Problem Solving Contest

IPSC 2018 Rules

This document contains detailed rules for IPSC 2018.

What is IPSC?

The IPSC is an online problem solving contest for teams consisting of up to three people.

Several problems will be published at the beginning of the competition. Each problem consists of a problem statement and some input files. To solve a problem you will have to compute correct output data for the given input data sets. Usually this means that you will write a program that solves the problem, but you may produce the output by hand or in any other way. Only the correctness of your output data will be judged.

When is IPSC?

The contest will take place from 6 October 2018, 15:00 UTC to 6 October 2018, 20:00 UTC. The contest takes 5 hours. Registration will be open until the end of the contest.

The practice session will take place from 5 October 2018, 13:00 UTC to 6 October 2018, 13:00 UTC. During this session, you can get acquainted with the contest environment and its technical details. Participation is optional, but recommended.

What should a team look like?

Each team should consist of at most three people. The contest is open for everybody, regardless of nationality, age, and education.

There are separate ranklists for individuals and for teams in the secondary school division (where all team members are students of a secondary school or younger).

What happens during the contest?

At the beginning of the contest we will publish a problem set consisting of between 10 and 20 problems.

The problem statements will be in English. If you are not fluent in English, you can invite someone to help you with translations.

Unless declared otherwise, each problem "X" has an easy subproblem "X1" and a hard subproblem "X2". For each subproblem, your goal is to create a correct output file and to submit it on the contest web page. Note that you only submit the output data, not a program.

We will then judge your submission and inform you whether it was correct or wrong. If you don't succeed, you can try again. Unless declared otherwise, you are allowed to make at most 10 submissions for each subproblem.

When judging the correctness of your output data, the exact type and amount of whitespace used does not matter (any sequence of whitespace characters is considered equal to a single space). Still, please follow the output specification as closely as possible.

If you think that the problem statement is ambiguous or that there are bugs in the test data, you may submit a clarification request using the e-mail address in the footer. (You can use English, Slovak or Czech.) If we agree that an ambiguity or an error exists, we will notify you. If the issue is important, a global clarification will also be published. Please watch the announcements page for such clarifications.

The organizers reserve the right to disqualify any team for any reason. (Usually, a team may be disqualified for breaking the rules, cheating, and any other activity that jeopardizes the IPSC contest.)

What is allowed during the contest?

You can use any editors, programming languages, libraries, tools or other software (as long as you already have a right to use it). Based on the statistics, some of the recommended languages are C++, Python, Java and C#. You can also use code you wrote before the contest, or software you paid for. All problems will be solvable using just free open source software.

Your team should use at most one computer per team member. Do not use larger clusters or clouds.

During the contest it is strictly forbidden to communicate about solving the problems with people outside your team. Violating this rule may lead to disqualification.

If you are not sure whether something is allowed, ask the organizers.

Who wins?

Teams are ranked according to the most points received. Teams which receive the same number of points are ranked by least total time.

Points are only awarded for solving subproblems. A team receives 1 point for each easy subproblem solved and 2 points for each difficult subproblem solved.

The total time is the sum of the time consumed for each solved subproblem. (There is no time consumed for a subproblem that is not solved.) If you submit the correct output for a subproblem T seconds after the contest starts, the time consumed is (T seconds) + (10 minutes) × (number of wrong submissions) × (points received for the subproblem).

Some special problems are scored differently. For example, solving some problems doesn't alter your points, but it decreases your total time. In such cases, their problem statements will contain an accurate description of their scoring.

Minus sixty minutes are awarded for sending the organizers a postcard before the contest starts (see "Postcard Quest" on the front page).