You are given two **non-empty** linked lists representing two non-negative integers. The digits are stored in **reverse order**, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list.

You may assume the two numbers do not contain any leading zero, except the number 0 itself.

**Example 1:**

**Input:** l1 = [2,4,3], l2 = [5,6,4]
**Output:** [7,0,8]
**Explanation:** 342 + 465 = 807.

**Example 2:**

**Input:** l1 = [0], l2 = [0]
**Output:** [0]

**Example 3:**

```
```**Input:** l1 = [9,9,9,9,9,9,9], l2 = [9,9,9,9]
**Output:** [8,9,9,9,0,0,0,1]

**Constraints:**

The number of nodes in each linked list is in the range [1, 100].

0 <= Node.val <= 9

It is guaranteed that the list represents a number that does not have leading zeros.

**Solution:**

```
class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
ListNode result = new ListNode(0);
ListNode p1 = l1;
ListNode p2 = l2;
ListNode curr = result;
int carry=0;
while(p1!=null || p2!=null)
{
int x = (p1!=null)?p1.val:0;
int y = (p2!=null)?p2.val:0;
int sum = carry+x+y;
carry = sum/10;
curr.next = new ListNode(sum%10);
curr=curr.next;
if(p1!=null) p1=p1.next;
if(p2!=null) p2=p2.next;
}
if(carry>0)
{
curr.next = new ListNode(carry);
}
return result.next;
}
}
```

## Comments