21. Merge Two Sorted Lists 注：代码来自leetcode
struct ListNode
* mergeTwoLists(struct ListNode
* l1, struct ListNode
* l2) {
if(l1
==NULL)
return l2;
if(l2
==NULL)
return l1;
if(l1
->val
<l2
->val)
{
l1
->next
=mergeTwoLists(l1
->next,l2);
return l1;
}
else
{
l2
->next
=mergeTwoLists(l1,l2
->next);
return l2;
}
}
