Merge Two Sorted Lists:
Merge
two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.
/** * 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) { // Start typing your C/C++ solution below // DO NOT write int main() function ListNode guard(-1); ListNode* pTail=&guard; while(l1&&l2) { ListNode*& tmp=l1->val<l2->val?l1:l2; pTail->next=tmp; pTail=pTail->next; tmp=tmp->next; } pTail->next=l1?l1:l2; return guard.next; } };