Fibonacci — Python Technical Interview Questions & Answers

Fibonacci

Fibonacci

  • Fibonacci is a classic practice problem. State the rule, trace a tiny input, then code. Fibonacci: next = sum of last two. Second largest: watch duplicates. Hanoi: move n-1, biggest, n-1. Distance: sqrt((x2-x1)**2 + (y2-y1)**2).
  • For Fibonacci: say the output for one small n before you write the loop. That is the exam.
  • Fibonacci — output: [0, 1, 1, 2, 3, 5]. Real sequence, not dummy numbers.

Technical Interview Tip: Rule + one dry-run + then code.

Code Examples for Fibonacci

Example

# Fibonacci
a, b = 0, 1
out = []
for _ in range(6):
    out.append(a)
    a, b = b, a + b
print(out)

Fibonacci — output: [0, 1, 1, 2, 3, 5]. Real sequence, not dummy numbers.

How to Explain Fibonacci to an Interviewer

Explain Fibonacci as if you are teaching a junior — definition, then one tiny script.

Fibonacci — know the rule. Fibonacci — tiny trace first.

What does the example print, and why?

Fibonacci — output: [0, 1, 1, 2, 3, 5]

What mistake do freshers make with Fibonacci?

Fibonacci — edge cases (n=0, duplicates).