#include <iostream>
using namespace std;

int main()
{
   double x;
   int wybor;
   bool petla = true;

   while( petla ){
       cout<<" Zamiana Jednostek\n";
       cout<<"1. Metry na milimetry\n";
       cout<<"2. Metry na centymetry\n";
       cout<<"3. Metry na decymetry\n";
       cout<<"4. By zakonczyc program\n";
       cin>>wybor;
       switch( wybor )
       {
       case 1:
           cout<<"Podaj ilosc metrow\n";
           cin>>x;
           cout<<x<<" metrow to "<<x*0.001<<" milimetrow.\n";
           break;
        case 2:
           cout<<"Podaj ilosc metrow\n";
           cin>>x;
           cout<<x<<" metrow to "<<x*0.01<<" centymetrow.\n";
           break;
        case 3:
           cout<<"Podaj ilosc metrow\n";
           cin>>x;
           cout<<x<<" metrow to "<<x*0.1<<" decymetrow.\n";
           break;
        case 4:
           petla = false;
           break;
        default:
            cout<<"Podano nieprawidlowa wartosc";
            break;
       }
       cout<<"\n";
   }

   return 0;
}









#include <iostream>
#include <cmath>
using namespace std;

int main()
{
    int a, b, c, x1, x2, delta = b*b-4*a*c;
    cout << "Podaj a: ";
    cin >> a;
     cout << "Podaj b: ";
    cin >> b;
  cout << "Podaj c: ";
    cin >> c;
    if(a==0)
    {
        cout<<"To nie jest rownanie kwadratowe";
    }
    else
    {
        if( delta > 0 )
        {
            x1=(-b-sqrt(delta))/(2*a);
            x2=(-b+sqrt(delta))/(2*a);
            cout<<"x1 = "<<x1<<"/n";
            cout<<"x2 = "<<x2;
        }

        else if(delta==0)
        {
            x1=-b/(2*a);
            cout<<"x0 = "<<x1;
        }

        else // delta < 0
        {
            cout<<"Brak rozwiazan";
        }
    }
    return 0;
}