基本链表操作
代码：
1 ListNode *addTwoNumbers(ListNode *l1, ListNode *l2) { 2 ListNode *h = NULL; 3 ListNode *t = NULL; 4 int carry = 0; 5 6 while (l1 && l2) { 7 ListNode *node = new ListNode((l1->val + l2->val + carry) % 10); 8 carry = (l1->val + l2->val + carry) / 10; 9 if (!h) 10 h = t = node; 11 else { 12 t->next = node; 13 t = t->next; 14 } 15 l1 = l1->next; 16 l2 = l2->next; 17 } 18 while (l1) { 19 ListNode *node = new ListNode((l1->val + carry) % 10); 20 carry = (l1->val + carry) / 10; 21 if (!h) 22 h = t = node; 23 else { 24 t->next = node; 25 t = t->next; 26 } 27 l1 = l1->next; 28 } 29 while (l2) { 30 ListNode *node = new ListNode((l2->val + carry) % 10); 31 carry = (l2->val + carry) / 10; 32 if (!h) 33 h = t = node; 34 else { 35 t->next = node; 36 t = t->next; 37 } 38 l2 = l2->next; 39 } 40 if (carry > 0) 41 t->next = new ListNode(carry); 42 43 return h; 44 }