AddTwoNumbers.java

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        return recursiveFunction(l1, l2, new ListNode(0), 0);
    }
    public ListNode recursiveFunction(ListNode l1, ListNode l2, ListNode result, int valorEx){
        if(l1 == null && l2 == null){
            if(valorEx != 0){
                result.val = valorEx;
            }
            return result;
        }else{
            getNext(l1, l2, result, valorEx);
        }
        return result;
    }
    private void getNext(ListNode ln1, ListNode ln2, ListNode result, int valorEx) {
        int valor = ln1 == null ? ln2.val :
                        ln2 == null ? ln1.val :
                            ln1.val+ln2.val;
        if(valor + valorEx >= 10){
            result.val = (valor + valorEx) % 10;
            valorEx = (valor + valorEx - result.val) / 10;
        }else{
            result.val = valor + valorEx;
            valorEx = 0;
        }
        if(ln1 == null && ln2 == null && valorEx!= 0)
            result.next = new ListNode(valorEx);
        if(ln1 != null && ln2 != null) {
            if (ln1.next == null && ln2.next == null && valorEx == 0) return;
            result.next = recursiveFunction(ln1.next, ln2.next, new ListNode(0), valorEx);
        }else if(ln1 != null && ln2 == null){
            if(ln1.next == null && valorEx== 0) return;
            result.next = recursiveFunction(ln1.next, null, new ListNode(0), valorEx);
        }else if(ln1 == null && ln2 != null){
            if(ln2.next == null && valorEx== 0) return;
            result.next = recursiveFunction(ln2.next, null, new ListNode(0), valorEx);
        }
    }
}