Congratulations to our TCO17 Algorithm Champion, xudyh

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How does it work?

The matches are similar to Topcoder Single Round Matches (SRMs) and are available in four programming languages: Java, C#, C++, and Python.

Each online and onsite round of competition consists of three phases: Coding Phase, Challenge Phase, and System Testing Phase.

Note: The format of these competition rounds is similar to the format of topcoder Single Round Matches.

Challenge Phase

The Challenge Phase is a timed event wherein each competitor has a chance to challenge the functionality of other competitors’ code.

A successful challenge will result in a loss of the original problem submission points by the defendant and a 50-point reward for the challenger. Unsuccessful challengers will incur a point reduction of 25 points as a penalty, applied against their total score in that round of competition.

During the online rounds, the Challenge Phase will last 15 minutes. During the onsite rounds, the Challenge Phase will last 10 minutes.

System Testing Phase

The System Testing Phase is applied to all submitted code that has not already been successfully challenged. If the topcoder System Test finds code that is flawed, the author of that code submission will lose all of the points that were originally earned for that code submission.

The automated tester will apply a set of inputs, expecting the output from the code submission to be correct. If the output from a coder’s submission does not match the expected output, the submission is considered flawed. The same set of input/output test cases will be applied to all code submissions for a given problem.

All successful challenges from the Challenge Phase will be added to the sets of inputs for the System Testing Phase.


Buffalo Niagara Medical Campus (BNMC)
Booz | Allen | Hamilton
Meituan Dianping

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