tictacreference.java

我们学校的TicTacToe的java作业描述

/*
  Written by: YG
  First written: 15/10/06
  Last modified: 15/10/06
*/

import sheffield.*;

public class TicTacReference {

    // constants
    private static final int BEGINNER = 1;	// beginner level
    private static final int MASTER = 2;	// master level

    // instance fields
    private int dimension;	// grid dimension
    private int playlevel;	// play level
    private int empty;		// integer symbol for empty box
    private int[][] box;	// internal references
    private int emptyBoxes;	// the number of boxes left empty

    // constructor
    public TicTacReference(int d, int l, int symbol) {
	dimension = d;
	empty = symbol;

	// play level must be either 1 or 2
	if (l==1) {
	    playlevel = BEGINNER;
	}
	else if (l==2) {
	    playlevel = MASTER;
	}
	else {
	    System.out.print("Warning: ");
	    System.out.println("the play level must be either 1 or 2.");
	    System.exit(0);
	}

	// initialise the reference
	box = new int[dimension][dimension];
	for (int x=0; x<dimension; x++) {
	    for (int y=0; y<dimension; y++) {
		box[x][y] = empty;
	    }
	}

	// initialise the number of empty boxes
	emptyBoxes = dimension*dimension;
    }

    // choose a move by the algorithm
    public TicTacIndex chooseAMove() {
	TicTacIndex b;

	// beginner level
	if (playlevel == BEGINNER) {
	    b = ramdomChoice();
	}

	// master level
	else {
	    b = ramdomChoice();
	}
	return(b);
    }

    // make a random choice from empty boxes
    private TicTacIndex ramdomChoice() {

	// choose indices of one empty box
	int i = 0;
	int j = 0;
	int count = 0;
	int choice = (int)(Math.random()*emptyBoxes);
	for (int x=0; x<dimension; x++) {
	    for (int y=0; y<dimension; y++) {

		// test if the box(x, y) is empty
		if (isEmpty(x, y)) {
		    if (count==choice) {
			i = x;
			j = y;
		    }
		    count++;
		}
	    }
	}

	// return the indices
	TicTacIndex b = new TicTacIndex(dimension);
	b.indexToString(i, j);
	return(b);
    }

    // test if the box(x, y) is empty
    public boolean isEmpty(int x, int y) {
	boolean flag = false;
	if (box[x][y]==empty) {
	    flag = true;
	}
	return(flag);
    }

    // set a symbol to box(x, y)
    public void setBox(int x, int y, int symbol) {
	box[x][y] = symbol;
	updateNumberOfEmptyBoxes();
    }

    // return a symbol for box(x, y)
    public int getBox(int x, int y) {
	return(box[x][y]);
    }

    // update the number of empty boxes
    public void updateNumberOfEmptyBoxes() {
	emptyBoxes--;
    }

    // return the number of empty boxes
    public int getNumberOfEmptyBoxes() {
	return(emptyBoxes);
    }

    // find the sequence length for a symbol around box(x, y)
    public int sequenceLength(int x, int y, int symbol) {
	int maxSequence = 0;

	// test left to right
	int count = 0;
	int i = x;
	while ((i>=0) && (box[i][y]==symbol)) {
	    count++;
	    i--;
	}
	i = x+1;
	while ((i<dimension) && (box[i][y]==symbol)) {
	    count++;
	    i++;
	}
	if (maxSequence < count) {
	    maxSequence = count;
	}

	// test up to down
	count = 0;
	int j = y;
	while ((j>=0) && (box[x][j]==symbol)) {
	    count++;
	    j--;
	}
	j = y+1;
	while ((j<dimension) && (box[x][j]==symbol)) {
	    count++;
	    j++;
	}
	if (maxSequence < count) {
	    maxSequence = count;
	}

	// test lower left to upper right
	count = 0;
	i = x;
	j = y;
	while ((i>=0) && (j>=0) && (box[i][j]==symbol)) {
	    count++;
	    i--;
	    j--;
	}
	i = x+1;
	j = y+1;
	while ((i<dimension) && (j<dimension) && (box[i][j]==symbol)) {
	    count++;
	    i++;
	    j++;
	}
	if (maxSequence < count) {
	    maxSequence = count;
	}

	// lower left to upper right
	count = 0;
	i = x;
	j = y;
	while ((i>=0) && (j<dimension) && (box[i][j]==symbol)) {
	    count++;
	    i--;
	    j++;
	}
	i = x+1;
	j = y-1;
	while ((i<dimension) && (j>=0) && (box[i][j]==symbol)) {
	    count++;
	    i++;
	    j--;
	}
	if (maxSequence < count) {
	    maxSequence = count;
	}

	// return the length of sequence
	return(maxSequence);
    }

    // main method for testing the class
    public static void main(String[] args) {

	// CODE MISSING

    }
}