大整数因子

#include<bits/stdc++.h>
using namespace std;
int main()
{
    char c[31];
    while(cin>>c)
    {
        int len = strlen(c), flag = 0;
        for(int i = 2; i <= 9; i++)
        {
            int yushu = 0;
            for(int j = 0; j < len; j++)///对于这里建议列竖式进行计算，就能看出余数的秘密(>^ω^<)喵
            {
                yushu = (yushu * 10 + (c[j] - '0')) % i;
            }
            if(yushu == 0)///看最后的余数是不是0是0就说明能整除
            {
                flag = 1;
                cout << i << " ";
            }
        }
        if(flag == 0)
            cout << "none";
        cout<<endl;
    }
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    char c[31];
    while(cin>>c)
    {
        int len = strlen(c), flag = 0;
        for(int i = 2; i <= 9; i++)
        {
            int yushu = 0;
            for(int j = 0; j < len; j++)///对于这里建议列竖式进行计算，就能看出余数的秘密(>^ω^<)喵
            {
                yushu = (yushu * 10 + (c[j] - '0')) % i;
            }
            if(yushu == 0)///看最后的余数是不是0是0就说明能整除
            {
                flag = 1;
                cout << i << " ";
            }
        }
        if(flag == 0)
            cout << "none";
        cout<<endl;
    }
    return 0;
}