login.cpp

#include <iostream>

int main()
{
    int proba = 0;
    const int max_prob = 3;
    std::string login;
    std::string haslo;
    while( true )
    {
        std::cout << "Podaj login: ";
        std::cin >> login;
        std::cout << "Podaj haslo: ";
        std::cin >> haslo;
        if( login == "login"
         && haslo == "haslo" )
        {
            std::cout << "Prawidlowe dane" << std::endl;
            break;
        } else if( proba < max_prob )
        {
            std::cout << "Dane nieprawidlowe "<< std::endl;
            std::cout << "Pozotalo szans "<< max_prob - ++proba << std::endl;
        } else
        {
            std::cout << "Konto zablokowane " << proba << std::endl;
            break;
        }
    }
    return 0;
}