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) {}
* };
*/
#include <iostream>
struct ListNode
{
int val;
ListNode *next;
ListNode(int x) : val(x), next(NULL) {}
};
class Solution
{
public:
ListNode *addTwoNumbers(ListNode *l1, ListNode *l2)
{
// return null if the list is null.
if (l1 == NULL || l2 == NULL)
{
return NULL;
}
// the start node
ListNode* ResultList = new ListNode(10);
int Carry = 0;
ListNode* Tail = ResultList;
//ListNode* Tail = l1;
int Result = 0;
while ((l1 != NULL) && (l2 != NULL))
{
Result = l1->val + l2->val + Carry;
Carry = Result / 10;
Result = Result % 10;
ListNode* Tmp = new ListNode(Result);
Tail->next = Tmp;
Tail = Tmp;
l1 = l1->next;
l2 = l2->next;
}
while (l1 != NULL)
{
Result = l1->val + Carry;
Carry = Result / 10;
Result = Result % 10;
ListNode* Tmp = new ListNode(Result);
Tail->next = Tmp;
Tail = Tmp;
l1 = l1->next;
}
while (l2 != NULL)
{
Result = l2->val + Carry;
Carry = Result / 10;
Result = Result % 10;
ListNode* Tmp = new ListNode(Result);
Tail->next = Tmp;
Tail = Tmp;
l2 = l2->next;
}
// add the carry
if (Carry == 1)
{
ListNode* Tmp = new ListNode(1);
Tail->next = Tmp;
}
//remove the start node
ListNode* Tmp = ResultList->next;
delete ResultList;
ResultList = Tmp;
return ResultList;
}
};
void Test()
{
ListNode *l1 = new ListNode(3);
ListNode *l2 = new ListNode(5);
Solution S1;
ListNode *result = S1.addTwoNumbers(l1, l2);
std::cout << "The result is " << result->val << std::endl;
}
原文：http://blog.csdn.net/sheng_ai/article/details/45046655