LeetCode-002两数相加 public ListNode addTwoNumbers(ListNod

public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
    ListNode res = new ListNode(0);
    ListNode head = res;//留住第一个结点
    int jw=0;//进位
    while(l1!=null||l2!=null||jw!=0){
        int var1 = l1==null?0:l1.val;
        int var2 = l2==null?0:l2.val;
        int temp = var1+var2+jw;
        head.next = new ListNode(temp%10);
        jw = temp/10;
        head=head.next;
        if(l1!=null){
            l1=l1.next;
        }
        if(l2!=null) {
            l2 = l2.next;
        }
    }
    return res.next;
}