/*

ID: 2

输入两个链表，输出两个链表相加的结果，如下：

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)

Output: 7 -> 0 -> 8

特别注意当Input为(0) + (0)的时候

*/

#include <iostream>

using namespace std;

struct ListNode {

int val;

ListNode *next;

ListNode(int x) : val(x), next(NULL) {}

};

class Solution {

public:

ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {

int a, b, c = 0;

ListNode *p1 = l1, *p2 = l2;

ListNode *head = NULL, *p = NULL;

while (true) {

if (p1) {

a = p1->val;

p1 = p1->next;

}

else {

a = 0;

}

if (p2) {

b = p2->val;

p2 = p2->next;

}

else {

b = 0;

}

cout << "a: " << a << endl;

cout << "b: " << b << endl;

int sum = a + b + c;

cout << "sum: " << sum << endl;

if (!p1 && !p2 && sum == 0) {

if (head == NULL) {

ListNode *listNode = new ListNode(0);

head = listNode;

}

break;

}

else {

ListNode *listNode = new ListNode(sum % 10);

c = sum / 10;

if (head == NULL) {

head = listNode;

p = head;

}

else {

p->next = listNode;

p = p->next;

}

}

}

return head;

}

};