add-two-numbers(单链表相加)

题目描述

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

/**
* Definition for singly-linked list.
* public class ListNode {
*     int val;
*     ListNode next;
*     ListNode(int x) {
*         val = x;
*         next = null;
*     }
* }
*/
public class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
ListNode newNode = new ListNode(0);
ListNode node = newNode;
int cap = 0;
while(l1 != null || l2 != null) {
if(l1 != null) {
cap += l1.val;
l1 = l1.next;
}
if(l2 != null) {
cap += l2.val;
l2 = l2.next;
}
node.next = new ListNode(cap % 10);
cap = cap / 10;
node = node.next;

}

if(cap != 0) {
node.next = new ListNode(cap);
}
return newNode.next;
}
}