(oJ)链表非负整型数据相加问题,oj判断我时间超时，帮忙分析一下,谢谢！！

/**

 * Definition for singly-linked list.

 * public class ListNode {

 *     int val;

 *     ListNode next;

 *     ListNode(int x) { val = x; }

 * }

 */



public ListNode addTwoNumbers(ListNode l1, ListNode l2) {

        int c=0;

        ListNode temp1=l1,temp2=l2,temp,sum=new ListNode(0);

        ListNode Sum=sum;

        

        while(temp1!=null&&temp2!=null)

        {

            temp=new ListNode((c+temp1.val+temp2.val)%10);

            c=(c+temp1.val+temp2.val)/10;

            sum.next=temp;sum=temp;

            temp1=temp1.next;temp2=temp2.next;

        }

        

        while(temp1!=null)

        {

            temp=new ListNode((c+temp1.val)%10);

            c=(c+temp1.val)/10;

            sum.next=temp;sum=temp;

        }

        

        while(temp2!=null)

        {

            temp=new ListNode((c+temp2.val)%10);

            c=(c+temp2.val)/10;

            sum.next=temp;sum=temp;

        }

        if(c!=0)

        {

            temp=new ListNode(c);

            sum.next=temp;

        }

        return Sum.next;

    }

public ListNode addTwoNumbers(ListNode l1, ListNode l2) {

    ListNode dummyHead = new ListNode(0);

    ListNode p = l1, q = l2, curr = dummyHead;

    int carry = 0;

    while (p != null || q != null) {

        int x = (p != null) ? p.val : 0;

        int y = (q != null) ? q.val : 0;

        int sum = carry + x + y;

        carry = sum / 10;

        curr.next = new ListNode(sum % 10);

        curr = curr.next;

        if (p != null) p = p.next;

        if (q != null) q = q.next;

    }

    if (carry > 0) {

        curr.next = new ListNode(carry);

    }

    return dummyHead.next;

}