Leet Code add two number

add two number

题目要求：
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.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

public class ListNode {
    int val;
    ListNode next=null;

    ListNode(int x) {
        val = x;
        next = null;
    }
 }

.

public class Solution {

public static void main(String[] args) {

    ListNode listNodeL1=new ListNode(1);
    ListNode listNodeL1_2=new ListNode(2);
    ListNode listNodeL1_3=new ListNode(3);
    listNodeL1.next=listNodeL1_2;
    listNodeL1_2.next=listNodeL1_3;
    listNodeL1_3.next=null;

    ListNode listNodeL2=new ListNode(1);
    ListNode listNodeL2_2=new ListNode(2);
    ListNode listNodeL2_3=new ListNode(3);
    listNodeL2.next=listNodeL2_2;
    listNodeL2_2.next=listNodeL2_3;
    listNodeL2_3.next=null;
    Solution solution = new Solution();
   ListNode rs= solution.addTwoNumbers(listNodeL1,listNodeL2);
    while (rs!=null){
        System.out.println(rs.val);
        rs=rs.next;
    }
}



public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
    ListNode rs=new ListNode(0);
    ListNode cur=rs;
    int carry = 0;
    int i = 0;
    int j = 0;
    while (l1 != null || l2 != null) {
        if (l1 != null) {
            i = l1.val;
            l1=l1.next;
        }
        if (l2 != null) {
            j = l2.val;
            l2 = l2.next;
        }
        int sum = i + j + carry; //如果大于10 进位

        cur.next=new ListNode(sum%10); //创建一个新的节点
        cur=cur.next; //把下个节点和当前节点连起来
        carry=sum/10;//算进位
    }
    if(carry>0) cur.next=new ListNode(carry);
    return rs.next;
}

}