请你将两个数相加,并以相同形式返回一个表示和的链表。
你可以假设除了数字 0 之外,这两个数都不会以 0 开头。
示例 1:
输入:l1 = [2,4,3], l2 = [5,6,4]
输出:[7,0,8]
解释:342 + 465 = 807.
示例 2:
输入:l1 = [0], l2 = [0]
输出:[0]
示例 3:
输入:l1 = [9,9,9,9,9,9,9], l2 = [9,9,9,9]
输出:[8,9,9,9,0,0,0,1]
提示:
每个链表中的节点数在范围 [1, 100] 内
0 <= Node.val <= 9
题目数据保证列表表示的数字不含前导零
/**
Definition for singly-linked list.
public class ListNode {
int val;
ListNode next;
ListNode() {}
ListNode(int val) { this.val = val; }
ListNode(int val, ListNode next) { this.val = val; this.next = next; }
}
*/
class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
ListNode retListNode = new ListNode();
ListNode preNode = retListNode;
ListNode retNode = retListNode;
ListNode l1Iter = l1;
ListNode l2Iter = l2;
int val = -1;
int addOne = 0;
while(l1Iter != null && l2Iter != null){
addOne = 0;
val = l1Iter.val + l2Iter.val + retListNode.val;
if(val >= 10){
val = val - 10;
addOne = 1;
}
retListNode.val = val;
ListNode node = new ListNode();
node.next = null;
node.val = addOne;
retListNode.next = node;
preNode = retListNode;
retListNode = retListNode.next;
l1Iter = l1Iter.next;
l2Iter = l2Iter.next;
}
if(l1Iter != null){
while(l1Iter != null){
addOne = 0;
val = l1Iter.val + retListNode.val;
if(val >= 10){
val = val - 10;
addOne = 1;
}
retListNode.val = val;
ListNode node = new ListNode();
node.next = null;
node.val = addOne;
retListNode.next = node;
preNode = retListNode;
retListNode = retListNode.next;
l1Iter = l1Iter.next;
}
}
if(l2Iter != null){
while(l2Iter != null){
addOne = 0;
val = l2Iter.val + retListNode.val;
if(val >= 10){
val = val - 10;
addOne = 1;
}
retListNode.val = val;
ListNode node = new ListNode();
node.next = null;
node.val = addOne;
retListNode.next = node;
preNode = retListNode;
retListNode = retListNode.next;
l2Iter = l2Iter.next;
}
}
if(preNode.next != null && preNode.next.val == 0){
preNode.next = null;
}
return retNode;
}
}