Nim Game Java

[xdeja]

What I have accomplished so far...

Design and implement a Nim class and a NimGame application to allow two human players to play the game of Nim. The game starts with four piles of stones. The first pile has 3 stones, the second pile has 5 stones, the third pile has 7 stones, and the last pile has 9 stones. The players take turns removing stones. On a single turn a player may only take stones from a single pile.
The loser of the game is the player to take the very last stone.

This is what I need help on, I entered this for the time being.. but it's obviously not the right way to do it.

A player may not take more than half the pile, except when it’s the last stone in the pile.

while ( stones >= 4 )
            {
               //Display error message, and ask user to re enter number.
               System.out.print("Invalid number, You can't take more than half the pile");
               stones = input.nextInt();
            }

Below is all the code I have.

package nimgame;

import java.util.Scanner;

public class NimGame
{
    public static int player = 1;
    public static int [] _board;

    public static void main(String[] args)
    {

        //Declare variables
        int pile = 0; //Which file to pick from
        int stones = 0; //How many stones to pick
        int counter = 0; //If the game is over or not



        //Scanner 
        Scanner input = new Scanner(System.in);

        NimClass myAssistant = new NimClass();
        myAssistant.displayBoard(); //Set board up

        //Begin loop
        while(counter == 0)
        {
        //Choose pile you want to remove stones from.
        System.out.print("Player " + player + " Please enter the pile you wish" +
                         " to remove from. (1, 2, 3 or 4)\n");
        //Get a pile number
        pile = input.nextInt();

          //Only allow user to enter a valid pile number.
          while (pile < 1 || pile > 4)
            {
               //Display error message, and ask user to re enter number.
               System.out.print("Invalid number, Please enter a pile # 1-4 ");
               pile = input.nextInt();
            }

        //Enter # of stones you want to remove.
        System.out.print("Player " + player + " Please enter the amount of" +
                          " stones you wish to remove\n");
        stones = input.nextInt();
        myAssistant.playerMove(pile, stones);

         //Only allow user to take half the pile.
          while ( stones >= 4 )
            {
               //Display error message, and ask user to re enter number.
               System.out.print("Invalid number, You can't take more than half the pile");
               stones = input.nextInt();
            }

            //Determine what player is entering the values.
            if (player == 1)
                player = 2;
            else
                player = 1;

             //Display board / determine the winner of the game.
             myAssistant.displayBoard();
             myAssistant.determineWinner();


            if (myAssistant.determineWinner() != -1)
                counter = 1;

        }


    }
}

package nimgame;

public class NimClass
{
    //Board for the game array
    public static int [] _board;

    
    public NimClass()
    {
   
        //Determing # of stones in each pile at the beginning.
        _board = new int [4];
        _board[0] = 3; //Pile 1  3 stones
        _board[1] = 5; //Pile 2  5 stones
        _board[2] = 7; //Pile 3  7 stones
        _board[3] = 9; //Pile 4  9 stones

        System.out.println("Welcome to the Game of Nim\n" +
                           "You'll need to first pick a pile\n" +
                           "Then select how many stones you wish to remove\n");
    }


   //Display the game board
    public void displayBoard()
    {
        for(int row = 0; row < 4; row++)
        {
            if(_board[row] == 0)
                System.out.print("    0    ");
            else
                System.out.print("     " + _board[row] + "   ");
        }
            //Print out the piles
            System.out.println("\n  Pile 1   Pile 2   Pile 3   Pile 4\n");

    }

    //Determine the player's moves
    public boolean playerMove (int pile, int stones)
    {
      if ((pile < 1) || (pile > _board.length))
      {
          return false;
      }

        if (_board[pile - 1] >= stones)
        {
          _board[pile - 1] -= stones;
          return true;
        }
     else
        {
          return false;
        }
    }


    //Determine the winner of the game
    public int determineWinner()
    {
        boolean complete = true;
        int winner = -1;

        //Checking the piles to see if they're empty.
        if((_board[0] == 0) && ( _board[1]== 0) && ( _board[2]==0) && ( _board[3]==0))

            winner = NimGame.player; //Determine winner
            complete = false;

        if(complete == false && winner == 1)
        {
            //Display the results of player 1 winning.
            System.out.println("Player 1 Wins!");
            winner = 0;
        }

        if(complete == false && winner == 2)
        {
            //Display the results of player 2 winning.
            System.out.println("Player 2 Wins!");
            winner = 0;
        }
        return winner;

    }
}

Any help would be appreciated!

[NormR1]

Do you have an algorithm or design for how you want you program to work?
Once you get that, we can help you when you having problems writing the program.

[insanely_sane]

This is my understanding of what you want: If the player tries to remove more than or half of how many ever stones there are left in a pile, it will show an error unless it is the last stone.

You will need to first calculate how many stones the 'half' is. So the following should be the pseudocode:

while ( stones is >= (the number of stones left in the pile) divided by 2)
{
if (the number of stones in the pile == 1)//which is the last stone left
break;//break out of the while loop and continue
else
//show error message
}

I haven't tested it but it sounds logically correct. Hope that helped.

[Taywin]

You could add as

while (stones is >= (the number of stones left in the pile divided by 2) and the number of stones left in the pile is > 0)

This case, you should not need the break in the loop.

[NormR1]

Is the OP still looking at this or are we talking to an empty room?

[Taywin]

Some people do not mark thread as solved once they get what they want. I would not expect anything about that... :P