[LeetCode] 21. 合并两个有序链表(Merge Two Sorted Lists)

本文已收录于 LeetCode刷题 系列，共计 28 篇，本篇是第 4 篇

本文已收录到：LeetCode刷题 专题

• 42. 接雨水 (Trapping Rain Water)
• [LeetCode] 2. 两数相加 2. Add Two Numbers
• [LeetCode] 19. 删除链表的倒数第N个节点 19. Remove Nth Node From End of List
• [LeetCode] 21. 合并两个有序链表(Merge Two Sorted Lists)
• [LeetCode] 24. 两两交换链表中的节点(Swap Nodes in Pairs)
• [LeetCode] 61. 旋转链表(Rotate List)
• [LeetCode] 82. 删除排序链表中的重复元素 II(Remove Duplicates from Sorted List II)
• [LeetCode] 83. 删除排序链表中的重复元素(Remove Duplicates from Sorted List)
• [LeetCode] 86. 分隔链表(Partition List)
• [LeetCode] 206. 反转链表(Reverse Linked List)
• [LeetCode] 92. 反转链表 II(Reverse Linked List II)
• [LeetCode] 147. 对链表进行插入排序(Insertion Sort List)
• [LeetCode] 203. 移除链表元素(Remove Linked List Elements)
• [LeetCode] 160. 相交链表(Intersection of Two Linked Lists)
• [LeetCode] 237. 删除链表中的节点 (Delete Node in a Linked List)
• [LeetCode] 328. 奇偶链表 (Odd Even Linked List)
• [LeetCode] 876. 链表的中间结点 (Middle of the Linked List)
• [LeetCode] 1290. 二进制链表转整数 (Convert Binary Number in a Linked List to Integer)
• [LeetCode] 141. 环形链表 (Linked List Cycle)
• [LeetCode] 142. 环形链表 II (Linked List Cycle II)
• [LeetCode] 283. 移动零 (Move Zeroes)
• [LeetCode] 496. 下一个更大元素 I (Next Greater Element I)
• [LeetCode] 503. 下一个更大元素 II (Next Greater Element II)
• [LeetCode] 456. 132模式 (132 Pattern)
• [LeetCode] 20. 有效的括号 (Valid Parentheses)
• [LeetCode] 94. 二叉树的中序遍历 (Binary Tree Inorder Traversal)
• [LeetCode] 144. 二叉树的前序遍历 (Binary Tree Preorder Traversal)
• [LeetCode] 145. 二叉树的后序遍历 (Binary Tree Postorder Traversal)

文章目录 隐藏

1 视频讲解

2 代码

视频讲解

代码

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) {
        ListNode dummy(0);
        ListNode* tail = &dummy;

        while (l1 != nullptr && l2 != nullptr)
        {
            if (l1->val < l2->val)
            {
                tail->next = new ListNode(l1->val);
                tail = tail->next;
                l1 = l1->next;
            }
            else
            {
                tail->next = new ListNode(l2->val);
                tail = tail->next;
                l2 = l2->next;
            }
        }
        while (l1 != nullptr)
        {
            tail->next = new ListNode(l1->val);
            tail = tail->next;
            l1 = l1->next;
        }
        while (l2 != nullptr)
        {
            tail->next = new ListNode(l2->val);
            tail = tail->next;
            l2 = l2->next;
        }
        return dummy.next;
    }
};

1. /**
2. * Definition for singly-linked list.
3. * struct ListNode {
4. * int val;
5. * ListNode *next;
6. * ListNode(int x) : val(x), next(NULL) {}
7. * };
8. */
9. class Solution {
10. public:
11. ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) {
12. ListNode dummy(0);
13. ListNode* tail = &dummy;
15. while (l1 != nullptr && l2 != nullptr)
16. {
17. if (l1->val < l2->val)
18. {
19. tail->next = new ListNode(l1->val);
20. tail = tail->next;
21. l1 = l1->next;
22. }
23. else
24. {
25. tail->next = new ListNode(l2->val);
26. tail = tail->next;
27. l2 = l2->next;
28. }
29. }
30. while (l1 != nullptr)
31. {
32. tail->next = new ListNode(l1->val);
33. tail = tail->next;
34. l1 = l1->next;
35. }
36. while (l2 != nullptr)
37. {
38. tail->next = new ListNode(l2->val);
39. tail = tail->next;
40. l2 = l2->next;
41. }
42. return dummy.next;
43. }
44. };

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) {
        ListNode dummy(0);
        ListNode* tail = &dummy;

        while (l1 != nullptr && l2 != nullptr)
        {
            if (l1->val < l2->val)
            {
                tail->next = new ListNode(l1->val);
                tail = tail->next;
                l1 = l1->next;
            }
            else
            {
                tail->next = new ListNode(l2->val);
                tail = tail->next;
                l2 = l2->next;
            }
        }
        while (l1 != nullptr)
        {
            tail->next = new ListNode(l1->val);
            tail = tail->next;
            l1 = l1->next;
        }
        while (l2 != nullptr)
        {
            tail->next = new ListNode(l2->val);
            tail = tail->next;
            l2 = l2->next;
        }
        return dummy.next;
    }
};

 

作者： 高志远

高志远，24岁，男生 查看高志远的所有文章