题解 | 大整数的因子

#include<iostream>
#include<cstdio>
#include<string>
using namespace std;
bool Function(string num,int k){
    int total=0;
    for(int i=0;i<num.size();i++){
        int digit =num[i]-'0';
        total *=10;
        total +=digit;
        total %=k;
    }
    return total ==0;
}
int main(){
    string num;
    int pos=0;
    while(getline(cin,num)){
        if(num[0] =='-'){
            cout<<"none"<<endl;
        }else{
            for(int k=2;k<=9;k++){
                if(Function(num,k)){
                    cout<<k<<" ";
                    pos++;
                }
            }
            if(pos==0){
                cout<<"none"<<endl;
                return 0;
            }
            getchar();
            cout<<endl;
        }
    }
    return 0;
}