21. Merge Two Sorted Lists

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

public class Solution {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        if(l1==null)
          return l2;
        if(l2==null)
          return l1;
        ListNode result = new ListNode(0);
        ListNode p1 = l1;
        ListNode p2 = l2;
        if(p1.val<p2.val)
          {
              result = p1;
              result.next = mergeTwoLists(p1.next,p2);
          }
        else
          {
              result = p2;
              result.next = mergeTwoLists(p1,p2.next);
          }
        return result;
    }
}