BattleShip game ship on top of ship

[linux1man]

Hi!

i am working on a text version battleship game, but my problem is the ships that are generated by the computer are placed one on top of another.
Does anybody have any solutions on how this can be fixed? :confused:

My code:

import java.util.Random;
 
 public class BattleShip
 {
 	public String[][] grid;
	private int[] takenX = new int[100];
	private int[] takenY = new int[100];
 	private int length;
 	private int width;
 	
 	public BattleShip(int l, int w)
 	{
 		grid = new String[l][w];
 		length = l;
 		width = w;
 		initGrid();
  	}
 	
 	public void initGrid()
 	{
 		for (int r = 0; r < grid.length; r++)
 			for (int c = 0; c < grid[r].length; c++)
 			{
 				grid[r][c] = "O";   
 			}
 	}
 	
 	public void printGrid()
 	{
 		String g = "";
 		g += "    ";
 		for (int i = 1; i <= (grid.length); i++)
 		{
 			g += (i + " ");
 		}
 		
 		g += "\n\n";
 		
 		for (int r = 0; r < grid.length; r++)
 		{
			if (r >= 9)
				g += ((r + 1) + "  ");
			else
				g += ((r + 1) + "   ");
 			for (int c = 0; c < grid[r].length; c++)
 			{
 				g += ((grid[r][c]) + " ");
 			}
 			g += "\n";
 		}
 		System.out.println(g);
 	}
	 
	public boolean isValidLocation(int l, int h)
	{
		if ((grid[l][h]).equals("O"))
			return false;
		else
			return true;
	}
	
	public void placeShip(int l)
	{
		Random rand = new Random();
		int x = rand.nextInt(10 - (l - 1)); 
		int y = rand.nextInt(10 - (l - 1));
		int dir = rand.nextInt(2) + 1;
		if (dir == 1)
		{
			for (int i = 0; i < l; i++)
			{
				grid[x + i][y] = "#";
			}
		}
		else
		{
			for (int j = 0; j < l; j++)
			{
				grid[x][y - 1] = "#";
			}
		}
	}
 	
 	public static void main(String[]args)
 	{
 		BattleShip battleship = new BattleShip(10,10);
 		battleship.placeShip(5);
 		battleship.printGrid();
 	}
 }

Any suggestions would be very helpful !!!!

[Fubarable]

Some suggestions:

1) Use either an enum for horizontal / vertical or a boolean such as "placeHorizontal" since there are only two possibilities, and a boolean or enum would be much more readable than dir == 1 or dir ==2.

2) Select horizontal vs. vertical placement first as it will effect the possible range of positions available for the ship on both axi. For instance, if the ship is of length 5 and you randomly place it horizontally, then there are 6 possible starting x locations, and 10 possible starting y locations. Conversely if the ship is to be placed vertically, then swap the previous statements.

3) Easiest I think is a placeShip method that repeatedly selects a random location until one is found that doesn't overlap. A do-while loop could work nicely here.

[Tolls]

And whichever way you choose (random placement is probably the easiest as said) make sure you deploy the larger ships first or you could find the code trying to deploy a battleship when there's no valid space left on the board.