Java code
class Solution {
public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
ListNode l = new ListNode(0);
ListNode temp = l;
while(l1 != null && l2 != null) {
if(l1.val < l2.val) {
temp.next = new ListNode(l1.val);
l1 = l1.next;
}
else {
temp.next = new ListNode(l2.val);
l2 = l2.next;
}
temp = temp.next;
}
while(l1 != null) {
temp.next = l1;
return l.next;
}
while(l2 != null) {
temp.next = l2;
return l.next;
}
return l.next;
}
}