### Changing the game's internal representation

No. 152

Q:

This exercise aims at changing the subsequent items with respect to the previous Tic-tac-toe solution:

End user perspective
1. End users are used to count from 1 to 9 rather than from 0 to 8. Consequently we should supply a different hint regarding the fields' numbering scheme:

 012 345 678 ⇒ 123 456 789
2. The two players should have a choice about who is to start a game:

Numbering scheme:

1|2|3
-+-+-
4|5|6
-+-+-
7|8|9

Who is going to start? 0 = June, other = Bill
0

June, please enter next field's number:
3. The numbering hints should appear right to the current tic-tac-toe board rather than on top of it. Furthermore only the remaining free fields shall be on offer. In the next example this restriction excludes position 4:

Player June(O)
vs. Bill(X)          Free fields

| |                   1|2|3
-+-+-                  -+-+-
O| |                    |5|6
-+-+-                  -+-+-
| |                   7|8|9

Bill, please enter next field's number:

A: