合并两个有序链表
1 /** 2 * Definition for singly-linked list. 3 * struct ListNode { 4 * int val; 5 * struct ListNode *next; 6 * }; 7 */ 8 9 10 struct ListNode* mergeTwoLists(struct ListNode* l1, struct ListNode* l2){ 11 if (l1 == NULL) 12 return l2; 13 if (l2 == NULL) 14 return l1; 15 struct ListNode *l=NULL; 16 if (l1->val < l2->val) { 17 l = l1; 18 l->next = mergeTwoLists(l1->next, l2); 19 } else { 20 l = l2; 21 l->next = mergeTwoLists(l1, l2->next); 22 } 23 return l; 24 }