合并两个排序的链表

 1 public class Solution {
 2     public ListNode Merge(ListNode p1,ListNode p2) {
 3         if(p1==null) return p2;
 4         if(p2==null) return p1;
 5         ListNode mhead = null;
 6         if(p1.val<p2.val){
 7             mhead = p1; mhead.next = Merge(p1.next,p2);
 8         }
 9         else{
10             mhead = p2;
11             mhead.next = Merge(p1,p2.next);
12         }
13         return mhead;
14     }
15 }