Программирование на языке С++, очень срочно

 #include <cmath> 
#include <iostream>

using namespace std;

struct Function { 
    double a = 0; 
    double x = 0; 
    void args(const double _a, const double _x) { 
        a = _a; 
        x = _x;  
    } 
private: 
    double f() const { 
        if (a > 0) return 2.0 * a * x + fabs(a - 1.0); 
        return exp(x) / sqrt(1.0 + pow(a, 2)) - 1.0; 
    } 
    friend ostream& operator<<(ostream& out, const Function& table) { 
        if (table.a <= 0) { 
            cout.setf(ios::fixed); 
            cout.precision(15); 
        } 
        return out << table.f(); 
    } 
};

double input(const char* prompt) { 
    cout << prompt; 
    double value; 
    cin >> value; 
    cin.ignore(0x1000, '\n'); 
    return value; 
}

int main() { 
    const auto x = input("x: "); 
    const auto a = input("a: "); 
    Function fn; 
    fn.args(a, x); 
    cout << "f(a, x) = " << fn << '\n'; 
}