LeetCode OJ：Add Two Numbers (相加链表之数)

 1 /**
 2  * Definition for singly-linked list.
 3  * struct ListNode {
 4  *     int val;
 5  *     ListNode *next;
 6  *     ListNode(int x) : val(x), next(NULL) {}
 7  * };
 8  */
 9 class Solution {
10 public:
11     ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
12         ListNode * curr = new ListNode(0);
13         ListNode * root = curr;
14         ListNode * prev = curr;
15         int currVal = 0;
16         while(l1 != NULL && l2 != NULL){
17             currVal = l1->val + l2->val;
18             curr->val += currVal;
19             curr->next = new ListNode(curr->val/10);
20             curr->val%=10;
21             prev = curr;
22             curr = curr->next;
23             l1 = l1->next;
24             l2 = l2->next;
25         }
26         while(l1 != NULL){
27             curr->val += l1->val;
28             curr->next = new ListNode(curr->val/10);
29             curr->val %= 10;
30             prev = curr;
31             curr = curr->next;
32             l1 = l1->next;
33         }
34         while(l2 != NULL){
35             curr->val += l2->val;
36             curr->next = new ListNode(curr->val/10);
37             curr->val %= 10;
38             prev = curr;
39             curr = curr->next;
40             l2 = l2->next;
41         }
42         if(curr->val == 0){
43             prev->next = NULL;
44             delete curr;
45         }
46         return root;
47     }
48 };