Judging for ACM Programming Contest

Lisong Xu (Based on Jeff's Link)
(Last Updated on October 31, 2011)

1. Installing Compilers on Your Laptop

    In the ACM programming contest, a team may use any of the following languages: Java, C, and C++. Accordingly, a judge should install the following software on his/her laptop: Java Development Kit (version 6 and up), gcc (version 3.4.4 and up), and g++(version 3.4.4 and up).
    Note that, if you have multiple Java software installed on your laptop, sometimes you may be confused with which one you are using. Therefore, I strongly suggest you first uninstall all Java Development Kits (JDKs) and all Java Runtime Environments (JREs) from your laptop, and then install the latest Java SE Development Kit.
    You may download and install the above compilers at the following sites. Depending on the network and your machine speed, this may take one to two hours. Thus, please do not wait until the last minute to install them!

    Windows Machines:

• Java SE Development Kit (JDK). Please download JDK, which includes java compiler. Note that you should add the java bin directory (e.g., "C:\Program Files\Java\jdk1.6.0_22\bin") into your "PATH" variable, and add the java lib directory (e.g., "C:\Program Files\Java\jdk1.6.0_22\lib") and the current directory (i.e., ".") into your "CLASSPATH" variable.
• gcc and g++ in CodeBlocks. Please download codeblocks-10.05mingw-setup.exe, which includes gcc and g++ compilers. Note that you should add the CodeBlocks bin directory (e.g., "C:\Program Files\CodeBlocks\MinGW\bin") into your "PATH" variable.
  

    Linux Machines:

• Java SE Development Kit (JDK)
• Usually, gcc/g++ have already been installed on your machine. Just make sure to upgrade them to the latest version.

    Mac Machines:

• Upgrade Java to the latest version
• gcc and g++ in the Xcode Package.

2. Installing PC² on Your Laptop

    PC² is the Programming Contest Control System developed at California State University, Sacramento in support of Computer Programming Contest activities of the ACM.

• Download PC² from here. (The latest one is V9.1.6)
• Install PC² by unzipping the PC² distribution (e.g., to "C:\"). Note that you should add the PC² lib directory (e.g., "C:\pc2-9.1.6\lib") into your "CLASSPATH" variable.

3. Configuring PC² for Training

    Now you are almost done! Just one more step to configure PC2, so that it can connect to the training server.

• Open file "pc2v9.ini" in the PC² root directory with a text editor
• Change the server from "localhost:50002" to "129.93.230.81:22"
• Save it
• Finally, move this file from the PC² root directory to the PC² bin directory!

4. On-Line Training for Judging

   Type the following commands in the command line to make sure that you have successfully installed everything:

• javac -version
• gcc -v
• g++ -v

    Start PC2 Judge in the PC2 installation directory

• pc2judge.bat (for Windows)
• ./pc2judge (for Linux and Mac)
  

    Type your assigned username and password. Now you should see a list of 12 "Unjudged Runs". All of them are collected by me from the previous local and regional programming contests. If you see less than 12 "Unjudged Runs", send me an email, and I will reset the training server.

    Please judge each of them by

• Selecting one run and clicking button "Request Run"
• Clicking button "Execute Run"
• Waiting for the output, and then clicking button "Compare" to find out whether the team's output is the same as the judge's answer.
• If so, select "Yes" from the list of "Select Judgement"
• Otherwise, select one of the following error types from the list of "Select Judgement".
  
  • No - Compilation Error: The program will not compile. (Very rarely, since a team can find it easily by themselves.)
  • No - Run-time Error:  During execution, a run-time error occurred, such as divide by 0 and Java exceptions. (Sometimes).
  • No - Time-limit Exceeded: The program takes longer than 2 minutes to execute. (Quite often for complicated inputs).
  • No - Wrong Answer: The program generates incorrect answer to the question. (Most often).
  • No - Output Format Error: The output was not formatted according to specifications, only if the problem specification explicitly requires some output format; otherwise, we do not care about the output format. (Sometimes)
  • No - Excessive Output: We do not use this one.
• In the contest, you should click button "Accept Selected" to complete your judging. However, in this training, you just click button "Close/Cancel" to cancel your judging so that other judges can still try it.

   Compare your judgment with the following correct judgment, if you have any questions, please feel free to contact me.

5. During the Actual ACM Programming Contest

• Before the contest, please change the server in pc2v9.ini to the contest server in order to connect to the contest server not the training server.
  
• During the contest, please read the statement of each problem, and report to the head judge immediately in the following cases:
  • The problem statement is wrong.
  • The problem statement is ambiguous.
  • The judge answer is wrong.
  • The judge answer is not unique.
• During the contest, please double check with other judges in the following cases:
  
  • There are multiple types of errors for a program, and you are not sure which one to choose. In general, please select the first error that you observed. But if a program has both "Wrong Answer" and "Output Format Error", it is recommended to select "Wrong Answer". 
  • If you want to give "Compilation Error" or "Run-Time Error" for a program, please ask another judge to try to compile and run it on a different machine/operating system to check whether you still have the same error.
    
  • If you want to give "Output Format Error", please talk to other judges to make sure that the problem statement explicitly requires the output format.
    

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