Bus Seat Arrangement with Numbers in chart – C# Algorithm – Find Seat is W, M, S from number is inputted

W M S | S M W

01 02 03 | 19 20 21

04 05 06 | 22 23 24

07 08 09 | 25 26 27

10 11 12 | 28 29 30

13 14 15 | 31 32 33

16 17 18 | 34 35 36

These are the seat arrangements for a bus. I have to write a C# algorithm – When user gives a number the algorithm should return the seat is W, M or S. Example – If user enters number 26 algorithm should return M. What will the fastest way to achieve this?

>Solution :

What about this?

public static char SeatId(int seatNumber)
{
    return seatNumber >= 19 
        ? "SMW"[(seatNumber-1) % 3]
        : "WMS"[(seatNumber-1) % 3];
}

Shorter but less readable:

public static char SeatId(int seatNumber)
{
    return --seatNumber >= 18 
        ? "SMW"[seatNumber % 3]
        : "WMS"[seatNumber % 3];
}