剑指offer-合并两个排序的链表

 1 /*
 2 struct ListNode {
 3     int val;
 4     struct ListNode *next;
 5     ListNode(int x) :
 6             val(x), next(NULL) {
 7     }
 8 };*/
 9 class Solution {
10 public:
11     ListNode* Merge(ListNode* pHead1, ListNode* pHead2)
12     {
13         if(pHead1 == NULL)
14             return pHead2;
15         if(pHead2 == NULL)
16             return pHead1;
17         ListNode* pHead = NULL;
18         if(pHead1->val >= pHead2->val){
19             pHead = pHead2;
20             pHead->next = Merge(pHead1, pHead2->next);
21         }
22         else{
23             pHead = pHead1;
24             pHead->next = Merge(pHead1->next, pHead2);
25         }
26         return pHead;
27     }
28 };