Salam everyone,

This blog is a simple and practical guide on how to practice competitive programming, how to learn new algorithms, when to read others’ code, and how to prepare for NOI / OI-style contests. Everything here is based on practice ideas, written in easy English, with no extra theory.

1. How to Learn a New Algorithm

Do NOT learn algorithms first. Learn them when you need them.

Correct way to learn an algorithm:

1. Pick a problem.
2. Think seriously for about 15 minutes.
3. If you are stuck, read the editorial.
4. If the editorial uses a new algorithm or idea you don’t know:

• Read one article about it (USACO Guide, CP-Algorithms, or CF blog).
• Understand the idea, not memorise it.
• Implement it in that same problem.

1. Move on to the next problem.

Why this works:

• You learn the algorithm in context.
• You remember when to use it, not just what it is.
• Important algorithms appear again naturally in future problems.

Do NOT:

• Study algorithms by topic first.
• Memorise without using.
• Spend many days only on theory.

2. How to Practice Daily (Exact Routine)

Main daily practice (most important)

Try to practice 90–180 minutes every day.

1. Open Codeforces Problemset.
2. Choose a rating range where you can solve about 30–40% of problems.
3. Sort problems by newest first.
4. Pick a problem.

For each problem:

• Think 15 minutes very seriously.
• If new ideas keep coming, continue.
• If you are stuck, read the editorial.
• Always implement the solution.
• Add a one-line comment: what did you learn from this problem?

Repeat 2–5 problems per day, depending on difficulty.

Extra daily thinking (optional but strong)

• Pick one harder problem.
• Think about it during:

• School

• Walking
• Shower
• No coding, only thinking.

This improves idea generation.

Weekly practice

• Join every Codeforces and AtCoder contest you can.
• Virtual the contests you miss.
• If preparing for NOI, do one OI-style virtual contest per week.

3. I Can’t Implement Myself — Should I See Others’ Code?

Short answer: Yes, but only in the correct order.

Correct order:

1. Try to implement the solution yourself first.
2. If:

• You understand the idea,
• But your code is messy or buggy,

1. Then:

• Look at one clean editorial or solution code.
• Only to understand structure.

1. Close it.
2. Rewrite the solution from scratch.

Never do this:

• Copy-paste code.
• Read others’ code before trying.
• Use others’ code as a shortcut.

Rule to remember: Idea from editorial is fine. Code from others is last resort. Always rewrite yourself.

4. How to Prepare for NOI

NOI is an OI-style contest:

• Long problems
• Subtasks
• Deep thinking
• Time management matters a lot

Main NOI preparation plan

1. Base practice (daily)

• Grind Codeforces problems using the 30–40% rule.
• This builds speed, idea generation, and confidence.

2. Weekly OI virtual (very important)

Once per week:

• Do one full OI-style contest.
• Treat it like a real contest:

• Read all problems.

• Go for subtasks.
• Manage time carefully.

After the contest:

• Upsolve only problems you can understand.
• Focus on why subtasks work and how to extend them.

OI time management strategy (example)

For 3 problems in 4 hours:

1. Read all problems (15 minutes).
2. Think about each for ~15 minutes.
3. Order them from easiest to hardest.
4. Spend about 1 hour per problem.
5. If after ~50 minutes you are still stuck:

• Implement subtasks.
• Move on.

Do not tunnel on one problem.

Key NOI skills to build

• Subtask thinking
• Partial solutions
• Brute force → optimisation
• Time allocation
• Staying calm for long contests

Final Rules to Remember

• Reading editorials is not cheating.
• Learning fast is better than solving alone.
• Implementation is mandatory.
• Live contests train independence.
• NOI needs long focus and subtask skill.
• Consistency matters more than talent.

Thanks for reading. I hope this helps you practice smarter and prepare better. Best of luck with your competitive programming journey.