Time Complexity · #44 · 2026-05-18

What's the Big-O?

TypeScript ·Difficulty 1/3

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.

n = arr.length. What is the SPACE complexity (excluding the input)?

function reverseInPlace<T>(arr: T[]): T[] {
  let left = 0;
  let right = arr.length - 1;
  while (left < right) {
    [arr[left], arr[right]] = [arr[right], arr[left]];
    left++;
    right--;
  }
  return arr;
}

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