source code test

/**
 * Sorts an array in ascending order using the Bubble Sort algorithm.
 *
 * Bubble Sort works by repeatedly stepping through the list, comparing
 * adjacent elements, and swapping them if they are in the wrong order.
 * This process repeats until the array is fully sorted.
 *
 * Time Complexity:
 *   - Best:    O(n)   — already sorted (with early exit optimization)
 *   - Average: O(n²)
 *   - Worst:   O(n²)
 *
 * Space Complexity: O(1) — sorts in place
 *
 * @param {number[]} arr - The array of numbers to sort
 * @returns {number[]} The sorted array (sorted in place)
 */
function bubbleSort(arr) {
  const n = arr.length;

  for (let i = 0; i < n - 1; i++) {
    let swapped = false;

    // Each pass bubbles the largest unsorted element to the end,
    // so we can shrink the inner loop by i each time.
    for (let j = 0; j < n - 1 - i; j++) {
      if (arr[j] > arr[j + 1]) {
        // Swap adjacent elements
        [arr[j], arr[j + 1]] = [arr[j + 1], arr[j]];
        swapped = true;
      }
    }

    // If no swaps occurred, the array is already sorted — exit early
    if (!swapped) break;
  }

  return arr;
}