Add two numbers

public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
	       int carry =0;
	 
	        ListNode newHead = new ListNode(0);//头结点
	        ListNode p1 = l1, p2 = l2, p3=newHead;
	 
	        while(p1 != null || p2 != null){
	        //10进制进位计算，carry代表进位数，先判断链表是否为空，不为空则取出他的数值，并与另一个链表 //的值相加，如果大于等于10，则当前位为他们的和carry%10,而进位数carry为sum/10
	            if(p1 != null){ 
	                carry += p1.val;
	                p1 = p1.next;
	            }
	 
	            if(p2 != null){
	                carry += p2.val;
	                p2 = p2.next;
	            }
	            p3.next = new ListNode(carry%10); //存储当前位
	            p3 = p3.next; //链表增长
	            carry /= 10;  //进位数
	        }
	 
	        if(carry==1) 
	            p3.next=new ListNode(1);
	 
	        return newHead.next;
	    }

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.