c++-add two numbers 两个链表相加
题目描述
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
这道题考察的是链表相加,最简单的方法就是用新的链表来存入数据,因此关键点在于链表的新建:
利用new来开辟存储空间,也就是堆:
/**
* 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 temp;
int flag=0;
ListNode* p=l1;
ListNode* q=l2;
ListNode* res_head = new ListNode(-1);
ListNode* res_tmp=res_head;
while(p!=NULL || q!=NULL || flag){
temp=(p?p->val:0)+(q?q->val:0)+flag;
flag=0;
if(temp>=10){
temp-=10;
flag=1;
}
ListNode* tmp = new ListNode(temp);
res_tmp->next=tmp;
res_tmp=res_tmp->next;
if(p) p = p->next;
if(q) q = q->next;
}
return res_head->next;
}
};
posted on 2017-12-26 20:10 sichenzhao 阅读(202) 评论(0) 编辑 收藏 举报