判断输出被3,5,7整除的数（输出哨兵变量判断）

#include
//本程序用来判断一个数是否能被3,5,7整除
//输出的核心思想在于将被3或5或7整除后来一个哨兵变量a赋值，来根据哨兵变量的值来判断输出
using namespace std;
int main() {
long a,x=0;
cin>>x;
if(x%30) {
a+=1;
}
if(x%50) {
a+=2;
}
if(x%7==0) {
a+=4;
}
switch(a) {
case 7:
cout<<“It’s divisible by 3,5,7”;
break;
case 1:
cout<<“It’s divisible by 3”;
break;
case 2:
cout<<“It’s divisible by 5”;
break;
case 4:
cout<<“It’s divisible by 7”;
break;
case 3:
cout<<“It’s divisible by 3,5” ;
break;
case 5:
cout<<“It’s divisible by 3,7”;
break;
case 6:
cout<<“It’s divisible by 5,7”;
break;
default:
cout<<“null”;
}
return 0;
}