Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.
Example:
1
2
|
Input: 1->2->4, 1->3->4
Output: 1->1->2->3->4->4
|
合并两条已排序的链表，返回新链表，新链表必须包含两个链表的所有节点。
分析：涉及到头节点的操作，删除或者更改新增，都可以考虑创建一个dummy = new ListNode(0)，最后返回dummy.next，逻辑上不容易出错。详细代码如下：
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
|
class {
public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
ListNode dummy = new ListNode(0);
ListNode head = dummy;
while (l1 != null && l2 != null) {
if (l1.val < l2.val) {
head.next = l1;
l1 = l1.next;
} else {
head.next = l2;
l2 = l2.next;
}
head = head.next;
}
if (l1 != null) {
head.next = l1;
l1 = l1.next;
}
if (l2 != null) {
head.next = l2;
l2 = l2.next;
}
return dummy.next;
}
}
|
近期评论