WA #5 求调

#include <bits/stdc++.h>
using namespace std;

string x, y;

vector<int> a;
vector<int> b;
int c[510];

int main(){
	cin >> x >> y;
	for (int i = x.size() - 1; i >= 0; i--)
		a.push_back(x[i] - '0');
	for (int i = y.size() - 1; i >= 0; i--)
		b.push_back(y[i] - '0');
	for (int i = 0; i < max(a.size(), b.size()); i++){
		c[i + 1] += (a[i] + b[i] + c[i]) / 10;
		c[i] = (a[i] + b[i] + c[i]) % 10;
	}
	int flag = 0;
	for (int i = 510; i >= 0; i--){
		if (c[i] != 0)
			flag = 1;
		if (flag == 1)
			cout << c[i];
	}
	if (flag == 0)
		cout << 0;
	return 0;
}