21. 合并两个有序链表
题目链接
来源:力扣(LeetCode)
链接:https://leetcode-cn.com/problems/merge-two-sorted-lists/
著作权归领扣网络所有。商业转载请联系官方授权,非商业转载请注明出处。
题目描述
题目分析
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode() : val(0), next(nullptr) {}
* ListNode(int x) : val(x), next(nullptr) {}
* ListNode(int x, ListNode *next) : val(x), next(next) {}
* };
*/
class Solution {
public:
ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) {
ListNode* dummy = new ListNode();
ListNode* p = dummy;
ListNode* p1 = l1;
ListNode* p2 = l2;
while(p1 != nullptr && p2 != nullptr){
if(p1->val < p2->val){
p->next = p1;
p1 = p1->next;
}else{
p->next = p2;
p2 = p2->next;
}
p = p->next;
}
if(p1 != nullptr){
p->next = p1;
}
if(p2 != nullptr){
p->next = p2;
}
return dummy->next;
}
};