Advanced Code Reading #algorithms #interviews #recursion

📐 Describing Algorithms

3 exercises — read algorithm implementations and describe the logic in plain English. Essential for technical interviews and pair programming.

0 / 3 completed

Describing algorithms — sequence language

"First, it checks / initialises / sorts…"
"On each iteration / pass, it compares…"
"If the condition is met, it returns / swaps / continues…"
"The base case is when… / The recursive case is…"
"This runs in O(n log n) time because…"

1 / 3

Read this binary search implementation. Which description uses the most natural and accurate English?

function binarySearch(arr, target) {
  let left = 0, right = arr.length - 1;
  while (left <= right) {
    const mid = Math.floor((left + right) / 2);
    if (arr[mid] === target) return mid;
    if (arr[mid] < target) left = mid + 1;
    else right = mid - 1;
  }
  return -1;
}

2 / 3

In a technical interview, you are asked to explain this recursive function in plain English. Which answer is the strongest?

function factorial(n) {
  if (n <= 1) return 1;
  return n * factorial(n - 1);
}

3 / 3

A new team member asks how this sorting algorithm works. Choose the most educational English explanation:

function bubbleSort(arr) {
  for (let i = 0; i < arr.length; i++) {
    for (let j = 0; j < arr.length - i - 1; j++) {
      if (arr[j] > arr[j + 1]) {
        [arr[j], arr[j + 1]] = [arr[j + 1], arr[j]];
      }
    }
  }
  return arr;
}