此篇文章為我的解題紀錄，程式碼或許並不是很完善

Leetcode - 21. Merge Two Sorted Lists

解題思路

使用recursive來將list連接起來，有點難解釋嗚嗚

我滴程式碼

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
/**
 * 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* list1, ListNode* list2) {
        if (list1 == NULL && list2 == NULL)
        {
            return NULL;
        }
        else if (list1 == NULL)
        {
            return list2;
        }
        else if (list2 == NULL)
        {
            return list1;
        }
        else
        {
            if (list1->val <= list2->val)
            {
                list1->next = mergeTwoLists(list1->next, list2);
                return list1;
            }
            else
            {
                list2->next = mergeTwoLists(list1, list2->next);
                return list2;
            }
             
        }
    } 
};