Hello Codeforces users!
ZQFMGB12, nathanlo99 and I would like to invite everyone to write the Trudeau Logic Evaluation (TLE) 2016 September contest. The TLE is a monthly contest series written by high school students, predominantly from Pierre Elliott Trudeau High School, Canada. The contest serves as preparation for OI-style contests such as CCO and IOI. The contest will be hosted on the DMOJ platform.
The contest will consist of 6 problems, and the problem difficulty will range from Div. 2 A to Div. 1 C. All problems Only problems 4, 5, and 6 will have pretests, and partial points (in the form of subtasks) will be awarded!
The contest window will be 11 hours long and will last from 12:00 EDT to 23:00 EDT on September 21st, 2016. You may start your 3 hour interval at any time during this contest window, but be wary of the hard deadline at 23:00 EDT if you want to start late!
We hope you will enjoy the contest and will receive many AC solutions!
EDIT: fixed links.
EDIT 2: Problems 1, 2, and 3 will be run on full tests, and the contest window will start in 10 minutes. Please enjoy the contest!
EDIT 3: The contest is over, thank you to everyone who joined!
EDIT 4: Editorials are up! Please go to a problem page and click on "Read editorial" to view the editorial.
By the way, it's a rated contest.
How to solve the last problem? I think I reduced it to the following :
You have n variables with can be either 0 or 1. You have a few statements of the type
or 
where i, j, k are distinct. Determine if it's possible to assign the variables such that all the statements are correct and if it is possible, find one such solution.
I haven't personally solved this problem but I believe what you've reduced the problem to is the "3SAT problem", described here.
More specifically, the last problem can be reduced to an "XOR-satisfiability" problem. The challenge is finding a solution when multiple solutions exist.
Problem editorials are on their way! I need to wait until I have permission to post them on the DMOJ.
Update: I have uploaded the editorials on the respective problem pages.