Merge like the merge step of merge sort using two pointers.
Walk both lists, always attaching the smaller node to the result list. Append the remainder when one list ends.
At each step, the smallest remaining node must be the head of one of the two lists.
Merge like the merge step of merge sort using two pointers.
Walk both lists, always attaching the smaller node to the result list. Append the remainder when one list ends.
At each step, the smallest remaining node must be the head of one of the two lists.