function bubbleSort(arr, iteration) {
  if (iteration === 0) return;

  bubbleSwap(arr, 0, 1, iteration);
  bubbleSort(arr, iteration - 1);
}


function bubbleSwap(arr, i, j, n) {
  if (j >= n) return;

  // swap
  if (arr[i] > arr[j]) [arr[i], arr[j]] = [arr[j], arr[i]];

  bubbleSwap(arr, i + 1, j + 1, n);
}

const arr = [1, 8, 6, 5, 4, 9];

if (arr.length >= 1) bubbleSort(arr, arr.length)

console.log(arr)

// tc => O(n^2)