Persamaan Kuadrat C++

#include<iostream>
using namespace std;
int main(){
    int r,a,b,c,x;
    float D;
    cout<<"                    ==============================\n";
    cout<<"                   Menyelesaikan Persamaan Kuadrat"<<endl;
    cout<<"                    ==============================\n";
    cout<<endl;
    cout<<"Rumus = ax^2 + bx + c = 0";
    cout<<endl;
    cout<<"Masukkan nilai a =";
    cin>>a;
    cout<<"Masukkan nilai b =";
    cin>>b;
    cout<<"Masukkan nilai c =";
    cin>>c;
    D=(b*b)-4*a*c;
    r=D/2;
    cout<<"("<<b<<"*"<<b<<")"<<"-"<<"4"<<"*"<<a<<"*"<<c<<"="<<D<<endl;
    if(D==0){
    cout<<D<<"Akar Real"<<endl;
    }
    else if(D<0){
    cout<<D<<"Akar Tidak Real"<<endl;
    }
    else if(D*D){
    cout<<r<<"^"<<r<<" Akar Rasional"<<endl;
    }
   
    return 0;
}