Can you explain how to generate Fibonacci numbers iteratively?
Candidates describe an iterative solution to produce the Fibonacci sequence. This tests recursion vs iteration understanding and variable management.
Why Interviewers Ask This
This classic problem checks if candidates know how to avoid the exponential time complexity of naive recursion. Interviewers want to see optimization skills and the ability to manage state variables effectively. It also reveals their grasp of dynamic programming concepts even at a basic level.
How to Answer This Question
Describe initializing the first two numbers and iterating from the third position. In each step, calculate the next number by summing the previous two and update the variables. Avoid storing all numbers unless required. Highlight the O(n) time and O(1) space benefits over recursive solutions.
Key Points to Cover
- Initialization of base cases
- Iterative summation
- Variable updates
- Efficiency over recursion
Sample Answer
To generate Fibonacci numbers iteratively, I start by initializing the first two numbers, typically 0 and 1. Then, I loop from the third position up to N. In each iteration, I calculate the next number by adding the last…
Common Mistakes to Avoid
- Using recursion without memoization
- Incorrect initial values
- Storing unnecessary history
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