Object-oriented Software in Ada 95

9 Case study: Design of a game
This chapter looks at the implementation of the game reversi. The problem is analysed using the fusion
methodology and from this analysis and design is developed a program to play the game of reversi
between two human players.
9.1 Reversi
In the game of reversi two players take it in turn to add counters to a board of 8-by-8 cells. Each player has a stack
of counters, black one side and white the other. One player’s counters are placed white side up, whilst the other
player’s are black side up. The object of the game is to capture all your opponent's counters. You do this by
adding one of your counters to the board so that your opponent's counter(s) are flanked by two of your counters.
When you do this, the counters you have captured are flipped over to become your counters. If you can't capture
any of your opponent's counters during your turn, you must pass and let your opponent go.
The game is won when you have captured all your opponent's counters. If neither player can add a counter to
the board, then the player with the most counters wins. If the number of counters for each player is equal, then the
game is a draw.
The initial starting position is set so that the 4 centre squares in the 8-by-8 board of cells is as illustrated in
Figure 9.1.
Figure 9.1 The 4 center squares of a reversi board..
On a reduced board of 4-by-4 cells a game might be as illustrated in Figure 9.2.
Black’s move
White’s move
Black’s move White’s move Black’s move
© M A Smith - May not be reproduced without permission