Description
You are given two non-empty linked lists representing two non-negative integers. 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.
You may assume the two numbers do not contain any leading zero, except the number 0 itself.
Example
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4) Output: 7 -> 0 -> 8 Explanation: 342 + 465 = 807.分析
大数相加 用链表存储.
code
#include<iostream>
class Solution
{
public:
ListNode *addTwoNumbers(ListNode *l1, ListNode *l2)
{
ListNode preHead(0), *p = &preHead;
int extra = 0;
while (l1 || l2 || extra)
{
int sum = extra + (l1 ? l1->val : 0) + (l2 ? l2->val : 0);
p->next = new ListNode(sum % 10);
p = p->next;
extra = sum / 10;
l1 = l1 ? l1->next : l1;
l2 = l2 ? l2->next : l2;
}
return preHead.next;
}
};