// Source : https://oj.leetcode.com/problems/add-two-numbers/
// Author : Hao Chen
// Date : 2014-06-18
/**********************************************************************************
*
* You are given two linked lists representing two non-negative numbers.
* The digits are stored in reverse order and each of their nodes contain a single digit.
* Add the two numbers and return it as a linked list.
*
* Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
* Output: 7 -> 0 -> 8
*
**********************************************************************************/
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode *addTwoNumbers(ListNode *l1, ListNode *l2) {
int x=0, y=0, carry=0, sum=0;
ListNode *h=NULL, **t=&h;
while (l1!=NULL || l2!=NULL){
x = getValueAndMoveNext(l1);
y = getValueAndMoveNext(l2);
sum = carry + x + y;
ListNode *node = new ListNode(sum%10);
*t = node;
t = (&node->next);
carry = sum/10;
}
if (carry > 0) {
ListNode *node = new ListNode(carry%10);
*t = node;
}
return h;
}
private:
int getValueAndMoveNext(ListNode* &l){
int x = 0;
if (l != NULL){
x = l->val;
l = l->next;
}
return x;
}
};