/**
* 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) {
if(l1==NULL){
return l2;
}
else if(l2==NULL){
return l1;
}
else if(l1->val>l2->val){
l2->next=mergeTwoLists(l1,l2->next);
return l2;
}
else{
l1->next=mergeTwoLists(l1->next,l2);
return l1;
}
}
};
