LeetCode 2 Add Two Numbers
Problem
You are given twonon-emptylinked lists representing two non-negative integers. The digits are stored inreverse orderand 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.
Solution
简单链表
/**
* 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 up = 0;
ListNode* head = new ListNode(0);
ListNode* now = head;
while(l1!=NULL || l2!=NULL){
int v1=0,v2=0;
if(l1!=NULL)
v1 = l1->val;
if(l2!=NULL)
v2 = l2->val;
int sum = v1 + v2 + up;
now->next = new ListNode(sum%10);
up = sum/10;
now = now->next;
if(l1!=NULL)
l1 = l1->next;
if(l2!=NULL)
l2 = l2->next;
}
if(up)
now->next = new ListNode(1);
return head->next;
}
};
