C#

tswright1041 wrote:

[ “IF (TB1 = A) do A = 1;” // “else If (TB1 = B) do B = 2” // else “IF (TB1 = C) do C = 3;” // “else If (TB1 = D) do D = 4” ect ].

class TheaterBooking
{
    const char MAX_ROW = 'P';
    const int MAX_SEAT = 18;

    IDictionary<char,IList<int>> m_bookedSeats;

    public TheaterBooking()
    {
        m_bookedSeats = new Dictionary<char,IList<int>>();
    }

    public bool IsValidNewBooking(char row, int seat)
    {
        if (row > MAX_ROW) throw new ArgumentException("Invalid row specified.", row);
        if (seat > MAX_SEAT) throw new ArgumentException("Invalid seat number specified.", seat);

        if (!IsValidSeat(row, seat))
            return false;

        if (IsAlreadyBooked(row, seat))
            return false;
        
        return true;  // The seat is valid for the row, and it is not already booked, so it is a valid new booking
    }

    private bool IsValidSeat(char row, int seat)
    {
        if (row <= 'H' && seat > 15)
            return false;
        return true;
    }

    private bool IsAlreadyBooked(char row, int seat)
    {
        IList<int> filledSeats;
        if (m_bookedSeats.TryGetValue(row, out filledSeats))
        {
            if (filledSeats.Contains(seat)) // This checks if row/seat is already booked
                return false;
        }

        return true;
    }
}