Merge Two Sorted Lists

问题描述

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.

算法

代码一

 1 public ListNode mergeTwoLists(ListNode l1,ListNode l2){
 2         if(l1==null)
 3             return l2;
 4         if(l2==null)
 5             return l1;
 6         ListNode l3,p;
 7         if(l1.val<=l2.val){
 8             l3=l1;
 9             p=l1;
10             l1=l1.next;
11         }else{
12             l3=l2;
13             p=l2;
14             l2=l2.next;
15         }
16         while(l1!=null&&l2!=null){
17             if(l1.val<=l2.val){
18                 p.next=l1;
19                 l1=l1.next;
20                 p=p.next;
21             }else{
22                 p.next=l2;
23                 l2=l2.next;
24                 p=p.next;
25             }
26         }
27         if(l1==null){
28             p.next=l2;
29         }else{
30             p.next=l1;
31         }
32         return l3;
33     }

代码二

 1 public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
 2     if (l1 == null || l2 == null) {
 3         return l1 == null ? l2 : l1;
 4     }
 5     ListNode head = null;
 6     if (l1.val < l2.val) {
 7         head = l1;
 8         head.next = mergeTwoLists(l1.next, l2);
 9     } else {
10         head = l2;
11         head.next = mergeTwoLists(l1, l2.next);
12     }
13     return head;
14 }

 

posted on 2015-11-11 15:22  qiaoshanzi  阅读(104)  评论(0)  编辑  收藏  举报

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