算法：两数相加

LeetCode  OJ ProblemAdd： Two Numbers

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

class Solution {
public:
    ListNode *addTwoNumbers(ListNode *l1, ListNode *l2) {
        if(l1 == NULL)
            return l2;
        else if(l2 == NULL)
            return l1;
        int flag = 0;   //记录进位
        ListNode *p, *pre_p, *r;
        pre_p = p = l1;
        r = l2;
        while(p && r)
        {
            if(flag)
                p->val += r->val + 1;
            else
                p->val += r->val;
            if(p->val >= 10)
            {
                p->val -= 10;
                flag = 1;
            }
            else
                flag = 0;
            
            pre_p = p;
            p = p->next;
            r = r->next;
        }
        if(!r && !p)
        {
            if(flag)
                pre_p->next = new ListNode(1);
        }
        else
        {
            if(!p)
            {
                pre_p->next = r;
                p = r;
            }
                
            if(flag)
            {
                while(p && flag)
                {
                    p->val += 1;
                    if(p->val >= 10)
                    {
                        p->val -= 10;
                        flag = 1;
                    }
                    else
                        flag = 0;
                    pre_p = p;
                    p = p->next;
                }
                if(!p && flag)
                    pre_p->next = new ListNode(1);
            }
        }
        
        return l1;
        
    }
};

 

算法：两数相加,布布扣,bubuko.com

算法：两数相加

原文：http://blog.csdn.net/wan_hust/article/details/23965673