CSCI A201/A597 Lecture Notes Eighteen Second Summer 2000

import java.io.*; 
import java.util.*; 

class Nim {
    public static void main(String[] args) {

	ConsoleReader console = new ConsoleReader(System.in); 

	Random generator = new Random(); 

	int height = Math.abs(generator.nextInt()) % 90 + 10; 

	PileOfMarbles pile = new PileOfMarbles(height); 

	System.out.println("You are working with a pile of height: " 
			   + pile.report());

	int number, currentHeight; 

	while (true) {

	    System.out.println("*** Computer moves."); 

	    System.out.println("Pile of marbles of height: " + pile.report()); 

	    currentHeight = pile.report(); 

	    if (currentHeight == 1) { 
              number = 1; 
            } else { 
              number = Math.abs(generator.nextInt()) % (currentHeight / 2) + 1; 
            } 

	    System.out.println("Computer chooses to remove: " 
			       + number + " marbles.");

	    pile.move(number); 
	    System.out.println("--------------------------"); 

	    System.out.println("*** Now the user has to move."); 

	    System.out.println("Pile of marbles of height: " + pile.report()); 
	    System.out.print("Please enter number of marbles you want to take: "); 
	    number = console.readInt(); 

	    pile.move(number); 
	    System.out.println("--------------------------"); 

	} 
    } 
} 

class PileOfMarbles {

    int height; 

    PileOfMarbles (int height) {
	this.height = height; 
    }

    int report() {
	return this.height;
    } 

    void move(int number) {

	System.out.println("***Removing " + number + " marbles from the pile."); 

	if (number <= 0 || 
            ((number > height / 2) && (number != 1))) {

	    System.out.println("***Bad move: you lose."); 
	    System.exit(0); 

	} else {

	    this.height -= number; 
	    if (this.height == 0) {
		System.out.println("***End of game: you lost.");
		System.exit(0); 
	    } 

	} 

	System.out.println("Pile of marbles is now: " + this.report());

    } 

} 

class ConsoleReader { 
    public ConsoleReader(InputStream inStream) { 
        reader = new BufferedReader(
                   new InputStreamReader(
                     inStream));     
    }
    public String readLine() { 
        String inputLine = "";
        try {
            inputLine = reader.readLine(); 
        } catch (IOException e) {
            System.out.println(e); 
            System.exit(1); 
        } 
        return inputLine; 
    }
    public int readInt() { 
        String inputString = readLine(); 
        int n = Integer.parseInt(inputString); 
        return n; 
    }
    public double readDouble() { 
        String inputString = readLine(); 
        double x = Double.parseDouble(inputString); 
        return x; 
    } 
    private BufferedReader reader; 
}

... To be continued by Adrian German for A201

Last updated: July 19, 2000 by Adrian German for A201