Add Two Numbers


#1

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 contain a single digit. Add the two numbers and return it as a linked list.

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

Example:

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
Explanation: 342 + 465 = 807.

#2
/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func addTwoNumbers(l1 *ListNode, l2 *ListNode) *ListNode {
    if l1==nil{return l2}
    if l2==nil{return l1}
    newHead := &ListNode{Val : 0}
    anchor := newHead
    var sum int
    for l1!=nil || l2!=nil{
        if l1!=nil{ 
            sum += l1.Val
             l1 = l1.Next
        }
        if l2!=nil{ 
            sum+= l2.Val
            l2 = l2.Next
        }
        newHead.Next = &ListNode{Val:sum%10}
        newHead = newHead.Next
        sum = sum/10
    }
    if sum>0{ newHead.Next = &ListNode{Val: sum}}
    newHead = newHead.Next
    return anchor.Next
}