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Internet Problem Solving Contest

IPSC 2013 Rules

This document contains detailed rules for IPSC 2013.


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 8 June 2013, 10:00 UTC to 8 June 2013, 15:00 UTC. The contest takes 5 hours. Registration will be open until the end of the contest.

The practice session will take place from 7 June 2013, 8:00 UTC to 8 June 2013, 9:00 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 divison (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 to be 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?

The golden rule is: If you solve a task and somebody else does not solve it, the reason must be "they did not have your skills", and not "they did not have your tools". If even after using the golden rule you are not sure whether something is allowed, ask the organizers.

You will certainly need a small number of computers with internet access (recommended: one per team member).

It is allowed to use both online resources (such as Google, Wikipedia, MathWorld, Wolfram Alpha) and offline resources (such as algorithm textbooks and Alice in Wonderland), provided they are reasonably available to the general public.

It is allowed to use any software that is reasonably available to the general public, including standard libraries of various programming languages, and also including software where you have to buy a license in order to use it. (It is guaranteed that all tasks will be solvable using just free open source software.)

It is very likely that you will write some computer programs in order to solve most of the tasks. Be prepared for that. (Based on the statistics, some of the recommended languages are C++, Python, Java or C#.)

It is allowed (and advised) to have a sufficient supply of food and drinks.

During the contest it is strictly forbidden to communicate with people other than your team members about issues that concern solving the problems. Violating this rule may lead to disqualification.

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) × (difficulty) where the difficulty is 1 for easy and 2 for hard subproblems.

Some special tasks are scored differently. For example, solving some tasks 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).