leetcode-hot链表专题——21.合并两个有序链表

21.合并两个有序链表

ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) {
         ListNode newHead(0);
         ListNode *p = &newHead;
        while(l1 && l2){
            if(l1->val > l2->val) swap(l1,l2);
            p->next=l1;
            l1=l1->next;
            p=p->next;
        }
       p->next=l1?l1:l2;
       return newHead.next;
    }