• C++ solution for problem A.
• Java solution for problem B.
• C solution for problem C.

If you have questions, feel free to send email to the coaches about any of these.

The general idea for the solution for problem C is:

1. Compute an interior point (arithmetic mean of all points works)
2. Find the angle to each vertex
3. Sort in increasing order
4. Output the sorted list starting from the rightmost vertex -- may have to wrap around if the rightmost vertex is not the first one in the sorted list.

All files used for this contest can be found here. The .in files are the input files the judges used to test your programs. The corresponding expected output is in the .out files. Try them out with your programs!