TopCoder介绍

From Wikipedia, the free encyclopedia

TopCoder is a company which administers contests in computer programming. TopCoder hosts weekly online algorithm competitions — known as SRMs or "single round matches" — as well as weekly competitions in design and development. The work in design and development produces useful software which is licensed for profit by TopCoder. Competitors involved in the creation of these components are paid royalties based on these sales. The software resulting from algorithm competitions — and the less-frequent marathon matches — is not usually directly useful, but sponsor companies sometimes provide money to pay the victors. Statistics (including an overall "rating" for each developer) are tracked over time for competitors in each category.

Types of competitions

• Algorithms (competition length 2 hours): Competitors are given a set (usually three) of algorithmic problems and have 75 minutes to correctly solve as many as they can.
• Design (competition length 1 week): Competitors are given a set of user requirements and attempt to convert them into a usable software design specification. Their efforts are judged on a variety of "real-world" criteria on how correct and practical their design is.
• Development (competition length 1 week): Competitors are given a set of design specification and attempt to write software components that match those specification. These components are judged on their functionality and coding style.
• Marathon Matches (competition length 1 week): Contestants are given a particularly difficult algorithmic problem. The scoring is done by computer based on criteria specifically suited to the problem.

Algorithm competitions

TopCoder has been hosting algorithm competitions since 2001. Each SRM consists of four phases:

• Coding phase (75-85 minutes): Coders write programs to solve three short problems using C++, Java, C#, or Visual Basic. Each problem set consists of an easy, medium, and hard question, the difficulty of which is reflected in each problem's point value. The problems' point values vary from match to match; a common point value distribution is 250-500-1000. Also, the quicker a coder writes a given problem, the more points that coder gets.

• Intermission (5 minutes): After the coding phase ends, there is a short break before the challenge phase begins. This time can be used to think of challenge cases.

• Challenge phase (10-15 minutes): Coders can challenge the submitted problems of other participants in their room by constructing test cases in an attempt to generate erroneous output. The challenger receives 50 points for a successful challenge, and loses 25 points for an unsuccessful challenge. If a coder's solution is successfully challenged, that coder receives no points for the problem. Each successful challenge is added to the set of tests to be run during the system testing phase.

• System-testing phase: Each problem that survives through the challenge phase is run on many test cases. If a coder's solution fails the system tests, that coder receives no points for the problem.

At the end of the contest, ratings are updated to incorporate each participating coder's performance.

Component design and development competitions

TopCoder hosts design and development competitions in which coders can compete to create components and applications that are either generally useful, or that third parties have contracted for.

TopCoder design and development competitions are week-long competitions. New components are posted every Thursday, and coders can choose a component from a list of Java and .NET components, and they have a week to design or develop their chosen component. Each week new components are posted. Development components are generally components that have been designed in a previous component design contest.

Marathon matches

Larger problems than are asked during a traditional TopCoder algorithm round are posted. They provide a more flexible competition format with an extended timeline.

Tournaments

• Google Code Jam: Each summer Google sponsors a set of TopCoder competitions with qualifying rounds and a tournament structure. Google has also held regional Code Jams restricted to Europe, Latin America, China and India.
• TopCoder Open: An annual event which features algorithm, design, and development competitions in a tournament structure, culminating in a live finale for the top competitors.
• TopCoder Collegiate Challenge: An annual event in which college students compete for money and school glory.
• TopCoder High School: An annual event in which high school students compete for scholarship and school glory. This tournament is started on 2007

Prizes

TopCoder initially awarded money every week to coders who did well in the weekly competitions, or Single Round Matches (SRMs). For a while, prize money was only awarded twice a year to winners and finalists of the TopCoder Collegiate Challenge (TCCC, which is in the spring) and the TopCoder Open (formerly the Invitational, which is in the fall). As of June 2005, some weekly SRMs began to once again award prize money, being sponsored by outside companies such as Google and Yahoo!.

Statistics

Although 100,000 people^[3] have registered as members at TopCoder website as of December 14, 2006 - less than 18% of them have participated in at least one algorithm competition with only 5% were active (participated during last 6 months). Even less have participated in component design (0.3%) and development (0.6%)^[4].

 Competitions, ratings, and divisions

In the early days, the Iron Man system was set up under which coders were grouped into rooms of ten according to skill level (determined by rating, similar to ELO chess rating), in order to encourage newcomers (who would have little hope of beating out the best coders for prize money) to stay and compete. After the contest, the 3 highest scoring coders in each room were paid according to the skill level of the room (winners in the room of contestants with the top 10 ratings were paid more than those in the room with coders 11-20, and so on). This created some paradoxical situations such as the possibility of coming fourth in the whole contest and getting no money, while the 111th placed contestant got paid, and gave rise to ratings diving. Ratings diving, or taking a ratings dive was accomplished simply by doing very poorly on purpose in a particular contest (by opening and not submitting any problems or submitting incorrect challenges). As a result, a contestant would, in their next contest, be placed in a room with 9 coders among whom they had a good chance of winning some money. The idea was that the dramatically increased chance of winning money made up for the fact that the money to be won was a lesser amount given the lower average rating of the room.

Coders have since been divided into two divisions, Division I and Division II. Division I consists of all coders with a rating of at least 1200, and Division II consists of all coders with a rating of 1199 or less. Coders are grouped in rooms with other members of their division, in groups of up to 20 coders in such a way that within each division, the average coder ratings in each of the rooms are roughly equal.

TopCoder as a business

The business plan behind TopCoder comprises several objectives. One goal is to be a recruitment center where companies can come to find programmers who are proven to be highly skilled, and where talented programmers can display their skills to a worldwide audience. Large companies sponsor TopCoder events to gain credibility with and exposure to talented developers. TopCoder also sells software licenses to use the growing body of components that have been developed in competition. Finally, TopCoder acts as an outsourcing center, allowing companies to farm out custom design and development tasks to TopCoder competitors.

See also

• ACM International Collegiate Programming Contest (ICPC)
• ICFP Programming Contest

References

1. ^ TopCoder management team. Retrieved on 2006-11-27.
2. ^ Topcoder Jobs and Profile. Yahoo! HotJobs. Retrieved on 2006-11-29.
3. ^ TopCoder Celebrates 100,000 Members.
4. ^ Member Search Results at TopCoder.

External links

• Official TopCoder website.