【剑指OFFER】合并两个排序的链表

 1 /*
 2 public class ListNode {
 3     int val;
 4     ListNode next = null;
 5 
 6     ListNode(int val) {
 7         this.val = val;
 8     }
 9 }*/
10 public class Solution {
11     public ListNode Merge(ListNode list1,ListNode list2) {
12         if (list1 == null) return list2;
13         if (list2 == null) return list1;
14         if (list1.val <= list2.val) {
15             list1.next = Merge(list1.next, list2);
16             return list1;
17         }else {
18             list2.next = Merge(list1, list2.next);
19             return list2;
20         }
21     }
22 }