tictactoe

Convert the non-OO into an object-oriented program

1. Create:

   • Cell class represents a cell of the board.
   • GameState enum represents all possible states of the game.
   • Seed enum represents all possible statuses of a cell. toString() is overwritten to simplify the printing of the board.
   • Board3x3 class represents the board.
   • Game class handles the game.
   • TTTOO2P3x3 class is the main entry into the game.
   • Classes hide attributes and expose necessary methods.

2. Follow good practices:

   • Meaningful naming, i.e. descriptive and pronounceable names
   • Top-down rule (public methods are on the top, then follow by private dependent methods)
   • Single responsibility principle
   • Avoid code duplication

Generalize the 3x3 tic-tac-toe game

The generalized version of tic-tac-toe supports boards of arbitrary sizes (m, n) and win condition (k consecutive cells of the same type). An important change compared to 3x3 OO version is that

private Cell playerMove(Seed seed) {

returns a Cell instead of void that helps the implementation of method

private void updateGame(Cell cell) {

Testing

Board has a method

public static boolean checkWin(Seed[] a, int currentCol, int winLength) {

that is used in checking whether a move leads to a win or not. Basically, given a array of seeds (a), an position in the array (index), and a win condition (winLength), this method returns true if there are winLength consecutive elements of a that have the same value as a[index]. The idea is that we start from index, move to the left, then the right, and count the number of consecutive cells of value a[index]. The algorithm will be stopped immediately when it found winLength such elements.

JUnitParams is utilized to test checkWin() for several cases.