Idea & Solution: rsj
Tutorial
Idea & Solution: rsj
Tutorial
Solution
Idea & Solution: rsj
Fact
Tutorial
Solution
Idea & Solution: jiangtaizhe001
Tutorial
Solution
1787E - The Harmonization of XOR
Idea & Solution: jiangtaizhe001, rsj
Tutorial
Bonus Problem
1787F - Inverse Transformation
Tutorial
Solution
Idea & Solution: rsj, 275307894a
Tutorial
Idea & Solution: jiangtaizhe001, rsj
Something To Say
Tutorial
Idea & Solution: 275307894a
Tutorial
I'm really sorry for the unsatisfactory problems and the tough 3 hours ;)
However, I still hope you can enjoy the problems after the contest. The editorial hasn't been fully checked, so feel free to comment if there're errors, typos or you have questions about them. We'll check them out tomorrow. Thanks!