SOURCE

function quickSort(arr, i, j){
  if(i < j){
    let l = i;
    let r = j;
    let t = arr[l];
    while(i < j){
      while(arr[j] >= t && i < j){
        j--
      }
      if(i < j){
        arr[i++] = arr[j]
      }
      while(arr[i] <= t && i < j){
        i++
      }
      if(i < j){
        arr[j--] = arr[i]
      }
    }
    arr[i] = t;
    quickSort(arr, l, i - 1);
    quickSort(arr, i + 1, r);
    return arr;
  }
}
document.write(quickSort([2,1,3,2,4,7,3], 0, 6))