高精度除以低精度

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;

vector <int> C;

void div(vector <int> &A, int b, int &r){
    r = 0; 
    for (int i = A.size() - 1; i >= 0; i -- )//注意和加减乘区分
    {
        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();
}

int main()
{
    string a;
    cin >> a;
    int b;
    cin >> b;
    vector <int> A;
    for (int i = a.size() - 1; i >= 0; i -- ) //注意每一次处理数据是数据成员的排列顺序
    A.push_back(a[i] - '0' );

    int r;

    div(A, b, r);

    for (int i = C.size() - 1; i >= 0; i -- )
    cout << C[i];

    cout << endl << r << endl;//输出余数

    return 0;
}