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.
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
- 题目大意
用两个非空的链表来表示两个非负整数，计算这两个数字的和并将其结果也用链表存储。注意：存储的数字是反向的，比如说 342 用链表来表示就是 2->4->3.
没有什么难度，就是小学时候学的多位数的加法。
/**
* Definition for singly-linked list.
* function ListNode(val) {
* this.val = val;
* this.next = null;
* }
*/
/**
* @param {ListNode} l1
* @param {ListNode} l2
* @return {ListNode}
*/
var addTwoNumbers = function (l1, l2) {
let carry = 0; //carry 用来记录进位
let head, node; //head 用来记录头指针
while (l1 || l2 || carry) { //当两个链表没有结束 或者 进位>0 继续循环
let sum = (l1 ? l1.val : 0) + (l2 ? l2.val : 0) + carry;
l1 && (l1 = l1.next);
l2 && (l2 = l2.next);
carry = parseInt(sum / 10);
let newNode=new ListNode(sum % 10);
if (!head){
head=newNode;
node=head;
}
else
node =( node.next =newNode);
}
return head;
};
