LeetCode | 21. Merge Two Sorted Lists
题目描述
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:
Input: 1->2->4, 1->3->4
Output: 1->1->2->3->4->4
思路
新建一个0节点用于存储结果
如果l1.val>l2.val，l1节点向后移一位
否则，l2节点向后移一位
代码
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
class Solution {
public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
ListNode ans = new ListNode(0);
ListNode cur = ans;
while(l1!=null && l2!=null) {
if(l1.val<l2.val) {
cur.next = l1;
l1 = l1.next;
}
else {
cur.next = l2;
l2 = l2.next;
}
cur = cur.next;
}
if(l1!=null) {
cur.next = l1;
}
if(l2!=null) {
cur.next = l2;
}
return ans.next;
}
}