编辑代码

/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} l1
 * @param {ListNode} l2
 * @return {ListNode}
 */
var addTwoNumbers = function(l1, l2) {
    let res = new ListNode(0,null);
    res.val = l1.val + l2.val;
    if(res.val >= 10){
        res.val = res.val -10;
        res.next = new ListNode(1,null);
    }
    let current = res;
    l1 = l1.next;
    l2 = l2.next;
    while(l1!==null&&l2!==null){
        if(!current.next){
            current.next = new ListNode();
        }
        current = current.next
        current.val = current.val + l1.val + l2.val;
        if(current.val >= 10){
            current.val = current.val - 10;
            current.next = new ListNode(1,null);
        }
        l1 = l1.next;
        l2 = l2.next;
    }
    return res
};