I’m not an expert in number theory,

but I was tired of feeling lost.

For a long time, I felt like I was studying in a very random way.

I would learn an idea, solve a few problems, then move on. After a while, I’d forget most of it.

So I decided to try something simple.

Instead of solving randomly, I started grouping problems by topic. Nothing fancy, just trying to build some structure.

For example, I made small sets around:

• Segmented Sieve
• Prime Factorization & Divisors
• Miller-Rabin & Pollard Rho
• Arithmetic on Graphs
• Some basic DP when needed

The goal is not to solve as many problems as possible. The goal is to understand the idea well enough so I don’t feel lost when I see it again.

Right now, I have a set where I solved 22 out of 26 problems, and I’m still stuck on some of them.

But honestly, this way feels much better than random practice.

I’m still learning, and I’m still adding more problems over time.

If you’re also struggling with number theory, maybe the problem isn’t difficulty, maybe it’s just the lack of structure.

I’m putting everything here, and I’ll keep updating it:

https://mirror.codeforces.com/group/abU6lmt4Ia/contests

If you have suggestions for good problems or topics I should add, I’d really appreciate it.