https://leetcode.com/problems/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.

思路：

考察链表操作，没啥说的。

AC代码：

1 /** 2  * Definition for singly-linked list. 3  * struct ListNode { 4  *     int val; 5  *     ListNode *next; 6  *     ListNode(int x) : val(x), next(NULL) {} 7  * }; 8  */ 9 class Solution {10 public:11     ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) {12         ListNode *p=new ListNode(0);13         ListNode *q=p;14         while(l1!=NULL && l2!=NULL){15             if(l1->val
     
      val){16                 q->next=l1;17                 q=q->next;18                 l1=l1->next;19             }20             else{21                 q->next=l2;22                 q=q->next;23                 l2=l2->next;24             }25         }26             if(l1!=NULL)27                 q->next=l1;28             else29                 q->next=l2;30             p=p->next;31             return p;32     }33 };