// Pay calculator
// Version 2.2
//
// New in this version: uses Version 1.4 of class Time, which
// includes, in particular, constructors and operators.

#include <fstream>
using std::ifstream;
using std::ofstream;
#include <iomanip>
using std::fixed;
using std::setprecision;
#include <iostream>
using std::cout;
using std::cin;
using std::istream;
using std::ostream;
#include <string>
using std::string;

const double kPayRate = 12;

class Time
{
public:
    friend istream & operator>>(istream & in, Time & t);

    Time() : Time(99, 99) {}
    Time(int h) : Time(h, 0) {}
    Time(int h, int m) : hours_(h), minutes_(m) {}

    int hours() const { return hours_; }
    int minutes() const { return minutes_; }

    void set_hours(int new_hours) { hours_ = new_hours; }
    void set_minutes(int new_minutes) { minutes_ = new_minutes; }

    void set(int new_hours, int new_minutes = 0);

private:
    int hours_;
    int minutes_;
};

inline void Time::set(int new_hours, int new_minutes)
{
    hours_ = new_hours;
    minutes_ = new_minutes;
}

inline double operator-(const Time & t1, const Time & t2)
{
    return (t1.hours() + t1.minutes()/60.0) -
        (t2.hours() + t2.minutes()/60.0);
}

inline istream & operator>>(istream & in, Time & t)
{
    in >> t.hours_;
    in.get(); // colon
    in >> t.minutes_;
    return in;
}

inline ostream & operator<<(ostream & out, const Time & t)
{
    out << t.hours() << ':';
    if (t.minutes() < 10) out << '0';
    out << t.minutes();
    return out;
}

int main()
{
    cout << "Name of input file: ";
    string input_file_name;
    getline(cin, input_file_name);

    ifstream ifs_input(input_file_name);
    if (!ifs_input) {
        cout << "Could not open file.\n";
        return 1;
    }

    cout << "Name of output file: ";
    string output_file_name;
    getline(cin, output_file_name);

    ofstream ofs_output(output_file_name);
    if (!ofs_output) {
        cout << "Could not open output file.\n";
        return 1;
    }

    int employee_number = -1;
    Time start_time, stop_time;

    while (ifs_input >> employee_number) {
        ifs_input >> start_time >> stop_time;

        double pay = (stop_time - start_time) * kPayRate;

        ofs_output << employee_number << ' '
                   << start_time << ' ' << stop_time << " $"
                   << fixed << setprecision(2) << pay << '\n';
    }

    return 0;
}