/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) {
ListNode *l3 = new ListNode(0), *l4 = l3;
int x,y;
while(l1!=NULL | l2 !=NULL)
{
if(l1 != NULL)
x = l1->val;
else
{
l3->next = l2;
break;
}
if(l2 != NULL)
y = l2->val;
else
{
l3->next = l1;
break;
}
if(x >= y)
{
l3->next = new ListNode(y);
l2 = l2->next;
}
else
{
l3->next = new ListNode(x);
l1 = l1->next;
}
l3 = l3->next;
}
return l4->next;
}
};