Original GPT Merge Implementation

function mergeSortedLists(list1: number[], list2: number[]): number[] {
  // create a new, empty list to store the merged and sorted result
  const mergedList: number[] = [];

  // create two pointers to keep track of the current index in each list
  let pointer1 = 0;
  let pointer2 = 0;

  // loop until one of the pointers reaches the end of its list
  while (pointer1 < list1.length && pointer2 < list2.length) {
    // compare the elements at the current pointers in each list
    if (list1[pointer1] <= list2[pointer2]) {
      // if the element in list1 is smaller or equal, add it to the merged list
      // and move the pointer in list1 forward
      mergedList.push(list1[pointer1]);
      pointer1++;
    } else {
      // otherwise, add the element from list2 to the merged list and move the
      // pointer in list2 forward
      mergedList.push(list2[pointer2]);
      pointer2++;
    }
  }

  // once one of the pointers has reached the end of its list, we can add the
  // remaining elements from the other list to the merged list
  while (pointer1 < list1.length) {
    mergedList.push(list1[pointer1]);
    pointer1++;
  }
  while (pointer2 < list2.length) {
    mergedList.push(list2[pointer2]);
    pointer2++;
  }

  // return the merged and sorted list
  return mergedList;
}