Hi Codeforces!

For those who don't know me, I competed at ICPC World Finals (2013 and 2015) and was a World Finals judge in 2018 and 2019. I've recently begun competitive programming again, and my hope is to regain international master or eventually grandmaster status.

One thing that helps me improve is writing "slow" analyses of problems I solve. Instead of just explaining the final solution, I try to reconstruct how I got there.. what I notice, what I try, where I mess up, and which insights eventually led to the solution. I did this when I trained for World Finals 2015, and it helped me improve quickly (peak rating 2396) and other people found them useful.

So I'm reviving them now, both to help my thinking as I hope to become good at cp again! And to help others who find most editorials a little too "fast".

I will mostly focus on Div. 1 A — D problems (which is where my skills are today, and most helpful for someone going from candidate master to international master) starting with:

• 2239A - Nim Game Is XOR Game — Analysis
• 2239B - Decidophobia — Analysis
• 2239C - Revival — Analysis
• 2239D - Hunting the Beast — Analysis

but I will have many more coming, and please feel free to message me in codeforces if you have a request for a specific problem.