高精度乘法

给定两个非负整数，请你计算它们的值。

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

void mul () {
    int m = a.size(), n = b.size();
    c = vector<int> (m + n);
    for (int i = 0; i < a.size(); i++) {
        for (int j = 0; j < b.size(); j++) {
            c[i + j] += a[i] * b[j];
        }
    }
    
    for (int i = 0, t = 0; i < c.size(); i++) {
        t += c[i];
        c[i] = t % 10;
        t /= 10;
    }
    
    while (c.size() > 1 && c.back() == 0) c.pop_back();
}

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');
    
    mul();
    
    for (int i = c.size() - 1; i >= 0; i--) cout << c[i];
    return 0;
}