Check if a given number is a Fibonacci number.
Updated Apr 28, 2026
Short answer
Check if 5n^2 + 4 or 5n^2 - 4 is a perfect square.
Deep explanation
Intermediate Fibonacci techniques focus on Dynamic Programming. Check if 5n^2 + 4 or 5n^2 - 4 is a perfect square.
Real-world example
Caching web service responses to identical queries.
Common mistakes
- Forgetting to pass the memo object in recursive calls.
Follow-up questions
- What is the time complexity with memoization?