Time Complexity · #51 · 2026-05-25

What's the Big-O?

JavaScript ·Difficulty 2/3

How to play

Read the code and pick its time complexity from four Big-O choices. Think about loops, recursion, and hidden costs. Press 1–4 or click to answer.

What is the time complexity of computing fib(n)?

function fib(n) {
  if (n <= 1) return n;
  return fib(n - 1) + fib(n - 2);
}

Loading your progress...

Press 1 through 4, or tap a numbered choice, to answer. Back to hub