tictacindex.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 TicTacIndex {

    // constants
    private static final int STRING_LENGTH = 2;	// string length

    // instance fields
    private String boxPosition;	// string representation of a box position
    private int x;		// x-axis index in the grid
    private int y;		// y-axis index in the grid
    private int maxIndex;	// maximum index allowed

    // constructor
    public TicTacIndex(int d) {
	boxPosition = null;
	x = 0;
	y = 0;
	maxIndex = d;
    }

    // test the length of the string
    public boolean testStringLength(String s) {
	boolean flag = true;
	if (s.length()!=STRING_LENGTH) {
	    flag = false;
	}
	return(flag);
    }

    // convert the string representation to integer indices
    public boolean stringToIndex(String s) {
	boxPosition = s;

	// convert the string
	x = boxPosition.charAt(0) - (int)'1';
	y = boxPosition.charAt(1) - (int)'a';

	// test if indices (x, y) are vaild
	boolean flag = testIndex(x, y);
	return(flag);
    }

    // test indices
    private boolean testIndex(int i, int j) {
	boolean flag = true;
	if ((i<0) || (maxIndex<=i) || (j<0) || (maxIndex<=j)) {
	    flag = false;
	}
	return(flag);
    }

    // convert integer indices to a string representation
    public void indexToString(int i, int j) {
	x = i;
	y = j;

	// convert to a string
	char[] c = new char[2];
	c[0] = (char)((int)'1' + x);
	c[1] = (char)((int)'a' + y);
	boxPosition = String.copyValueOf(c);
    }

    // return the x-axis index in the grid
    public int getX() {
	return(x);
    }

    // return the y-axis index in the grid
    public int getY() {
	return(y);
    }

    // return the string representation of a box position
    public String getBoxPosition() {
	return(boxPosition);
    }

    // main method for testing the class
    public static void main(String[] args) {
	EasyReader keyboard = new EasyReader();

	// read the grid dimension
	System.out.println("The grid dimension must be between 3 and 9.");
	int d = keyboard.readInt("  Enter the dimension: ");

	// read a string from the keyboard, then create an object
	String str = keyboard.readString("\n  Enter a string: ");
	TicTacIndex a = new TicTacIndex(d);

	// test the length of the string
	boolean flag = a.testStringLength(str);
	if (flag==false) {
	    System.out.println("\t\"" + str + "\" is not valid");
	}

	// convert a string representation to indices
	else {
	    flag = a.stringToIndex(str);
	    if (flag==false) {
		System.out.println("\t\"" + str + "\" is not valid");
	    }
	    else {
		System.out.print("\t(i, j) = ");
		System.out.println("(" + a.getX() + ", " + a.getY() + ")");
	    }
	}

	// read indices from the keyboard, then create an object
	int i = keyboard.readInt("\n  Enter the first index: ");
	int j = keyboard.readInt("  Enter the second index: ");
	TicTacIndex b = new TicTacIndex(d);

	// test if indices are valid
	flag = b.testIndex(i, j);
	if (flag==false) {
	    System.out.println("\t(" + i + ", " + j + ") is not valid");
	}

	// convert indices to a string representation
	else {
	    b.indexToString(i, j);
	    System.out.println("\tstring = \"" + b.getBoxPosition() + "\"");
	}
    }
}