这道题的第一个输入数据是123、123；输出数据是246。我在自己的编译器上运行结果是正确的。但到了洛谷上就WA了。 不知道咋错的，求助大佬。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string.h>
#include<map>
#include<algorithm>
using namespace std;
//a=1576492,b=6435412123
#define size 10000
int main()
{
	char a[size], b[size];
	int a1[size], b1[size], c1[size];
	memset(a1, 0, sizeof(a1));
	memset(b1, 0, sizeof(b1));
	memset(c1, 0, sizeof(c1));
	gets(a);
	gets(b);
	int len1 = strlen(a);
	int len2 = strlen(b);
	int max1 = max(len1, len2);
	int x = 0;
	for (int i = 0; i < len1; i++)//将a数组里的数字首尾互换
		a1[i] = a[len1 - i - 1] - 48;
	for (int i = 0; i < len2; i++)//将b数组里的数字首尾互换
		b1[i] = b[len2 - i - 1] - 48;
	for (int i = 0; i < max1; i++)
	{
		if (a1[i] + b1[i] + c1[i] < 10)  //不需要进位时的情况
			c1[i] = a1[i] + b1[i] + c1[i];
		else   //需要进位时的情况
		{
			if (i == max1-1)
			{
				x = 1;
				c1[i] = a1[i] + b1[i] +c1[i] - 10;
			}
			else
			{
				c1[i + 1] += 1;
				c1[i] = a1[i] + b1[i] +c1[i] - 10;
			}
		}
	}
	if (x != 0)
		cout << x;
	for (int i = max1 - 1; i >= 0; i--)
		cout << c1[i];
	return 0;
}