Merge Two Sorted Lists

https://leetcode.com/problems/merge-two-sorted-lists/

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.

 1 public class Solution {
 2     public static ListNode mergeTwoLists(ListNode l1, ListNode l2) {
 3         if(l1==null){return l2;}
 4         if(l2==null){return l1;}
 5         ListNode head=new ListNode(0);
 6         ListNode list1=l1;
 7         ListNode list2=l2;
 8         if(list1.val<=list2.val){head.next=l1;list1=list1.next;}
 9         else{head.next=list2;list2=list2.next;}
10         ListNode list=head.next;
11         while(list1!=null&&list2!=null){
12             if(list1.val<=list2.val){list.next=list1;list=list.next;list1=list1.next;}
13             else{list.next=list2;list=list.next;list2=list2.next;}
14         }
15         if(list1==null){list.next=list2;}
16         else if(list2==null){list.next=list1;}
17         return head.next;
18     }
19     public static class ListNode {
20     int val;
21     ListNode next;
22 
23     ListNode(int x) {
24         val = x;
25     }
26     }
27     public static void main(String[]args){
28     ListNode[]node=new ListNode[4];
29     for(int i=0;i<node.length;i++){
30         node[i]=new ListNode(i+2);
31     }
32     node[0].next=node[1];
33     node[1].next=node[2];
34     node[2].next=node[3];
35     ListNode node1=new ListNode(0);
36     ListNode node2=new ListNode(6);
37     node1.next=node2;
38     ListNode head=mergeTwoLists(node[0],node1);
39     while(head!=null){
40         System.out.println(head.val);
41         head=head.next;
42     }
43     }
44 }