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date: 2025-07-21 topics: [dsa, algorithms, logic, revision] day: 5

📘 Day 5 – Core DSA Pattern Revision

✅ What I Worked On

• Revisited 8 essential DSA problems, focusing on logic behind each
• Wrote down edge cases and dry-ran each problem
• Practiced by hand + IDE to reinforce patterns

📚 What I Learned

Problem	Pattern / Concept
Max in Array	Linear scan (compare & track)
Even/Odd	Use % 2 to check parity
Reverse Array	Two-pointer swap method
Prime Check	Loop till √n for efficiency
Fibonacci	Simple loop, track a and b
2nd Max	Track max and second max separately
Palindrome	Two pointers inward comparison
Bubble Sort	Repeated swaps until sorted

Each of these teaches classic logic + patterns like:

• Loop control
• Pointer movement
• Condition-based decisions
• Optimization by bounds

❌ Blockers

• Initially missed edge cases like:
  • Reversing odd-length arrays
  • Negative numbers for max
  • Prime of 1 and 0

🧠 Reflection

Solving DSA problems is great — but today I realized understanding the "why" and the "how" behind each approach is 10x more powerful. These core problems form the foundation for every complex question that comes later.

🔗 References / Code

• 🧠 DSA Revision Repo
• 🧠 DSA Repo