高精度加法

给定两个正整数（可能很大，超过long long 长度

#include <iostream>
#include <vector>
using namespace std;
vector<int> a, b, c;

void add () {
    int t = 0;
    for (int i = 0; i < a.size() || i < b.size() || t; i++) {
        if (i < a.size()) t += a[i];
        if (i < b.size()) t += b[i];
        c.push_back(t % 10);
        t /= 10;
    }
}

int main() {
    string x, y;
    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');
    
    add();
    
    for (int i = c.size() - 1; i >= 0; i--) cout << c[i];
    return 0;
    
}