leetcode3--Add Two Numbers

标签：leetcode   链表   存储   数据结构   指针   

<span style="font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; background-color: rgb(255, 255, 255);">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.</span>

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

题解：给定两个有序链表，将两个链表中对应节点得数据相加，进位制加入到下一个节点中，返回相加后得节点。

思路：首先想到解题得思路是，用两个指针遍历两个链表，取每个节点上得数据，进行相加，考虑是进位是否需要添加到下一个节点中。这其中应注意每个链表结束得判断，因为题目中为给出两个链表得长度是否相等。还有最后一次判断是否有进位，如果有得话就需要添加节点，具体代码如下：

/**
 * 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) {
        ListNode* ltmp = new ListNode(0);
        ListNode* pt = ltmp; //保存链表头
			int vtmp = 0;
			int htmp = 0;

			while(l1 !=NULL || l2 != NULL)
			{
			    if(l1 !=NULL)
			    {
			        vtmp += l1->val;
			        l1 = l1->next;
			    }
			    if(l2 != NULL)
			    {
			        vtmp += l2->val;
			        l2 = l2->next;
			    }
			    ltmp->next = new ListNode(vtmp % 10);
			    htmp = vtmp/10;
			    vtmp =htmp;
			    ltmp = ltmp->next;
			}
			if(htmp == 1)
			ltmp->next = new ListNode(1);
			return pt->next;
    }

};

leetcode3--Add Two Numbers

标签：leetcode   链表   存储   数据结构   指针   

原文地址：http://blog.csdn.net/shiyanwei1989/article/details/44515637