Resources for NOI preparation

🧠 BOOKS (for deeper or advanced understanding)

1. Programming Challenges – by Skiena & Revilla

• Classic CP book used in ICPC training.

• Problems are UVa-linked.

• Covers brute force, backtracking, DP, graphs, greedy.

2. CP3 (Competitive Programming 3) – by Steven & Felix Halim

• Very in-depth, more advanced than CPH.

• Great for older students or future preparation.

• Not ideal for beginners, but excellent for JC/Upper Sec.

3. USACO Guide (online, structured like a book)

🌐 https://usaco.guide

• Structured roadmap from Bronze to Platinum.

• Concepts + problem links + practice sets.

• Perfect for structured self-study.

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🌐 PRACTICE PLATFORMS

1. CSES Problem Set

🌐 https://cses.fi/problemset

• Created by Antti Laaksonen (CPH author)

• Clean, high-quality problems aligned with CPH chapters.

• Must-use.

2. AtCoder Beginner Contests (ABC)

🌐 https://atcoder.jp

• High-quality contests with accessible but elegant problems.

• Start from Contest 100 onward, solve ABCD problems.

3. Codeforces

🌐 https://codeforces.com

• Widely used by NOI and IOI participants.

• Good to train problem-solving speed + experience different problem styles.

• Start with Div 3 and 4.

4. CS Academy

🌐 https://csacademy.com/

• Visual problems, graph problems, interactive.

• Good for deeper practice (after basics covered).

5. DMOJ (Don Mills Online Judge)

🌐 https://dmoj.ca

• Canadian platform used in contests similar to NOI.

• Good progressive difficulty.

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🎥 VIDEO COURSES & EXPLANATIONS

1. Errichto’s YouTube Channel

🌐 https://www.youtube.com/@Errichto

• C++ expert, former ICPC Finalist.

• Explains DP, graphs, greedy, etc., clearly.

2. Codeforces EDU

🌐 https://codeforces.com/edu

• Structured modules for topics like Segment Trees, DSU, DP.

• More suitable from Month 3 onward.

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🔁 NOI & IOI PAST PROBLEMS

1. NOI Singapore Past Papers

🌐 https://noi.sg

• Most recent and relevant practice.

• Analyze problems with subtasks and time constraints.

2. IOI Archive

🌐 https://ioinformatics.org

• Try selected easier problems for stretch goals.

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🔧 IDEs & Tools

• C++ Online IDE: https://ideone.com or https://cpp.sh

• Local testing: Encourage to start compiling and testing locally with g++, especially before NOI.

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🎯 Suggested Mix