#include <bits/stdc++.h>
using namespace std;
const int MAXN = 5005;
int numA[MAXN],ans[MAXN];
int carry,sub;
int lenA;
string a;
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin>>a>>sub;
    if(a=="0"){
        cout<<0;
        return 0;
    }else if(sub==1){
        cout<<a;
        return 0;
    }
    lenA = a.size();
    a = ' '+a;
    for(int i = 1;i<=lenA;i++){
        numA[i] = a[i]-'0';
    }
    for(int i = 1;i<=lenA;i++){
        carry = carry*10+numA[i];
        ans[i] = carry/sub;
        carry = carry%sub;
    }
    int dir = 0;
    for(int i = 1;i<=lenA;i++){
        if(ans[i]!=0){
            dir =i;
            break;
        }
    }
    for(int i = dir;i<=lenA;i++){
        cout<<ans[i];
    }
    return 0;
}

这组测试数据是 9000000000 1000000000，正确输出是 9 但我的程序输出的是一堆 0，求问为什么