Дописать класс, добавить несократимую дробь и операторы сравнения для неё

#include <iostream>
#include <string>
using namespace std;
class drobi
{
    int a; 
    int b;
public:
      drobi operator +(drobi x);
      drobi operator -(drobi x);
      drobi operator /(drobi x);
      drobi operator *(drobi x); 
       void vvod();
       void vivod();
       void chast();
      drobi operator ^(int n);
      bool operator<(drobi x);
       };
int main()
{drobi a,b,x;
a.vvod(); b.vvod();
cout<<"Drob 1: ";
a.vivod();
cout<<endl;
cout<<"Drob 2: ";
b.vivod();
cout<<endl;
cout<<"A + B =";
x=a+b;
x.vivod();
cout<<" Pravil'naya: ";
x.chast();
cout<<endl;
cout<<"A - B =";
x=a-b;
x.vivod();
cout<<" Pravil'naya: ";
x.chast();
cout<<endl;
cout<<"A / B =";
x=a/b;
x.vivod();
cout<<" Pravil'naya: ";
x.chast();
cout<<endl;
cout<<"A * B =";
x=a*b;
x.vivod();
cout<<" Pravil'naya: ";
x.chast();
cout<<endl;
cout<<"A ^ 4 =";
x=a^4;
x.vivod();
x=b^4;
x.vivod();
cout<<endl;
system("PAUSE");
return 0;
}
/* Ââîä öèôð */
void drobi::vvod()
{
cout<<"Vvedite Chislitel: "<<endl; cin>>a;
if (a==0) 
{while (a==0) 
{cout<<" Nepravil'no vvedeno chislo. Nel'zya vvodit' 0. Povtorite vvod: ";
cin>>a;}}
cout<<"Vvedite Znamenatel: "<<endl; cin>>b;
if (b<0) 
{while (b<0)
{cout<<" Nepravil'no vvedeno chislo. Nel'zya vvodit' 0. Povtorite vvod: ";
cin>>b;}}
if (b==0)
{while (b==0)
{cout<<" Nepravil'no vvedeno chislo. Nel'zya vvodit' 0. Povtorite vvod: ";
cin>>b;}}
cout<<endl;
}
/* Âûâîä äðîáè */
void drobi::vivod()
{ 
cout<<a<<"/"<<b;
cout<<endl;
}
 
drobi drobi ::operator +(drobi x)
{drobi d;
if ((b%x.b!=0)&&(x.b%b!=0))
d.b=b*x.b;
else if (b>x.b) d.b=b; 
else if (b<x.b) d.b=x.b; 
else d.b=b;
d.a=a*(d.b/b)+x.a*(d.b/x.b);
return d ;
}
 
drobi drobi ::operator -(drobi x)
{drobi d;
if ((b%x.b!=0)&&(x.b%b!=0))
d.b=b*x.b;
else if (b>x.b) d.b=b; 
else if (b<x.b) d.b=x.b; 
else d.b=b;
d.a=a*(d.b/b)-x.a*(d.b/x.b);
return d ;
}
 
drobi drobi ::operator /(drobi x)
{drobi d;
d.a=a*x.b;
d.b=b*x.a;
return d;
}       
 
drobi drobi ::operator *(drobi x)
{drobi d;
d.a=a*x.a;
d.b=b*x.b;
return d;
}
 
void drobi::chast()
{int x;
x=0;
if (a>b)
{x=a/b;
a=a%b;}
if (x!=0)
cout<<x<<" "<<a<<"/"<<b<<endl;
else cout<<a<<"/"<<b<<endl;
}
 
drobi drobi:: operator ^(int n)
{drobi d; int i;
d.a=1;
d.b=1;
for(i=1;i<=n;i++)
d=d*(*this);
return d;
}
bool drobi::operator<(drobi x)
{
    return(x.a*b > x.b*a);
}