合并两个排序的链表

题目描述

输入两个单调递增的链表，输出两个链表合成后的链表，当然我们需要合成后的链表满足单调不减规则。

 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         ListNode temp = null;
15         ListNode head = null;
16         if(list1.val > list2.val){
17             temp =list2;
18             head =temp;
19             list2 = list2.next;
20         }else{
21             temp =list1;
22             head =temp;
23             list1 = list1.next;
24         }
25         while(list1 != null && list2 != null) {
26             if(list1.val > list2.val){
27                 temp.next = list2;
28                 temp=temp.next;
29                 list2=list2.next;
30             }else{
31                 temp.next = list1;
32                 temp=temp.next;
33                 list1=list1.next;
34             }
35         }
36         if(list1 == null){
37             temp.next = list2;
38         }else{
39             temp.next = list1;
40         }
41         return head;
42     }
43 }