高精度除以低精度

#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;
//b存商，r为余数
vector<int> div(vector<int> &a, int &b, int &r){
    vector<int> c;
    r = 0;

    for(int i = a.size() - 1; i >= 0; i -- ){
        r = r * 10 + a[i];
        c.push_back(r / b);
        r %= b;
    }

    reverse(c.begin(), c.end());
    while(c.size() > 1 && c.back() == 0) c.pop_back();
    // cout << c.back() << endl;
    return c;
}

int main(){
    string x;
    int b, r;
    cin >> x >> b;
    vector<int> a, c;
    for(int i = x.size() - 1; i >= 0; i -- ) a.push_back(x[i] - '0');

    c = div(a, b, r);

    for(int i = c.size() - 1; i >= 0; i -- ) printf("%d", c[i]);
    cout << endl << r;
    return 0;
}