tictacgrid.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 TicTacGrid {

    // constants
    private static final int MARGIN = 20;	// margin around the grid
    private static final int NUM_STEPS = 30;	// steps for drawing circles
    private static final int GRID_SIZE = 300;	// active grid size
    public static final int EMPTY = 0;		// integer symbol for empty box
    public static final int CROSS = 1;		// integer symbol for cross
    public static final int CIRCLE = 2;		// integer symbol for circle

    // instance fields
    private EasyGraphics grid;		// graphics window
    private int dimension;		// grid dimension
    private int playersChoice;		// either CROSS or CIRCLE
    private TicTacReference reference;	// internal reference
    private int crossLength;		// the cross sequence length
    private int circleLength;		// the circle sequence length

    // constructor
    public TicTacGrid(int d, int l, String p) {

	// d must be between 3 and 9
	if ((2<d) && (d<10)) {
	    dimension = d;
	}
	else {
	    System.out.print("Warning: ");
	    System.out.println("the grid dimension must be between 3 and 9.");
	    System.exit(0);
	}

	// p must be either 'x' or 'o'
	if (p.equals("x")) {
	    playersChoice = CROSS;
	}
	else if (p.equals("o")) {
	    playersChoice = CIRCLE;
	}
	else {
	    System.out.print("Warning: ");
	    System.out.println("the mark must be either \'x\' or \'o\'.");
	    System.exit(0);
	}

	// draw a grid
	int gridSize = GRID_SIZE+(MARGIN*2);
	double boxSize = GRID_SIZE/dimension;
	grid = new EasyGraphics(gridSize, gridSize, MARGIN, MARGIN);
	for (int x=1; x<dimension; x++) {
	    double tmp = boxSize*x;
	    grid.moveTo(0, tmp);
	    grid.lineTo(GRID_SIZE, tmp);
	    grid.moveTo(tmp, 0);
	    grid.lineTo(tmp, GRID_SIZE);
	}

	// create a reference
	reference = new TicTacReference(dimension, l, EMPTY);
    }

    // move by the player
    public boolean playerDoes(String s) {
	boolean flag = true;

	// test the string length
	TicTacIndex a = new TicTacIndex(dimension);
	flag = a.testStringLength(s);
	if (flag==false) {
	    System.out.println("\t\t\"" + s + "\" is not valid");
	}

	// convert the string to indices
	else {
	    flag = a.stringToIndex(s);
	    if (flag==false) {
		System.out.println("\t\t\"" + s + "\" is not valid");
	    }

	    // test if the box(x, y) is empty
	    else {
		int x = a.getX();
		int y = a.getY();
		flag = reference.isEmpty(x, y);
		if (flag==false) {
		    System.out.println("\t\t\"" + s + "\" is not empty");
		}

		// place a mark on the grid
		else if (playersChoice==CROSS) {
		    setCross(x, y);
		    reference.setBox(x, y, CROSS);
		    crossLength = reference.sequenceLength(x, y, CROSS);
		}
		else {
		    setCircle(x, y);
		    reference.setBox(x, y, CIRCLE);
		    circleLength = reference.sequenceLength(x, y, CIRCLE);
		}
	    }
	}

	// return the flag
	return(flag);
    }

    // move by the algorithm
    public String algorithmDoes() {

	// choose a move
	TicTacIndex b = reference.chooseAMove();

	// move by the algorithm
	int x = b.getX();
	int y = b.getY();

	// place a mark on the grid
	if (playersChoice==CROSS) {
	    setCircle(x, y);
	    reference.setBox(x, y, CIRCLE);
	    circleLength = reference.sequenceLength(x, y, CIRCLE);
	}
	else {
	    setCross(x, y);
	    reference.setBox(x, y, CROSS);
	    crossLength = reference.sequenceLength(x, y, CROSS);
	}

	// return the move
	return(b.getBoxPosition());
    }

    // fill a cross in a box
    private void setCross(int x, int y) {
	double boxSize = GRID_SIZE/dimension;

	// draw a cross
	grid.moveTo(boxSize*(x+0.3), boxSize*(y+0.3));
	grid.lineTo(boxSize*(x+0.7), boxSize*(y+0.7));
	grid.moveTo(boxSize*(x+0.3), boxSize*(y+0.7));
	grid.lineTo(boxSize*(x+0.7), boxSize*(y+0.3));
    }

    // fill a circle in a box
    private void setCircle(int x, int y) {
	double boxSize = GRID_SIZE/dimension;
	double radius = boxSize/5;
	double theta = 2.0*Math.PI/(NUM_STEPS-1);

	// draw a circle
	grid.moveTo(boxSize*(x+0.5)+radius, boxSize*(y+0.5));
	for (int i=1; i<NUM_STEPS; i++) {
	    grid.lineTo(boxSize*(x+0.5)+radius*Math.cos(theta*i),
			boxSize*(y+0.5)+radius*Math.sin(theta*i));
	}
    }

    // the game continues while (1) the sequence is shorter than the grid
    // dimension and (2) there are empty boxes
    public int gameOver() {
	int winner = -1;

	// cross wins
	if (crossLength>=dimension) {
	    winner = CROSS;
	}

	// circle wins
	else if (circleLength>=dimension) {
	    winner = CIRCLE;
	}

	// no box left empty
	else if (reference.getNumberOfEmptyBoxes()==0) {
	    winner = EMPTY;
	}

	return(winner);
    }
}