/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
ListNode head = new ListNode();
ListNode next = new ListNode();
head.next = next;
ListNode l1 = list1;
ListNode l2 = list2;
while(l1 != null && l2 != null){
int v1 = l1.val;
int v2 = l2.val;
if(v1 < v2 ){
next.next = l1;
l1 = l1.next;
}else{
next.next = l2;
l2 = l2.next;
}
next = next.next;
}
if(l1 != null){
next.next = l1;
}
if(l2 != null){
next.next = l2;
}
return head.next.next;
}
}
