Thread: Need help placing mines and another point on a field!!

i need to fill up 1/10th of the board with mines but i am only able to successfully put 1! also my goal is not showing up on the game even though i put it as an up arrow.

package Homework4;
 
import java.util.Random;
import java.util.Scanner;
 
 
public class HW4 {
 
	//Creates a new type to be used to create the board
	//We know that the board can only take on the value of Empty, Player, Walked_Path, and Goal
	//Thus it is better to use an enum and define these types instead of using an integer or a string
	//which would take up a lot of space in memory
	enum Spaces {Empty, Player, Walked_Path, Goal, mine};
	public static final int BOARD_SIZE = 10;
	//
	public static final double mine = (BOARD_SIZE*BOARD_SIZE)/10;
 
 
	public static void main(String[] args) {
		// TODO Auto-generated method stub
 
		//Keep track of the number of moves made by the player
		int numberOfMoves = 0;
		//The player's location
		int pX = 0;
		int pY = 0;
		//The target location
		Random r = new Random();
		int tX = r.nextInt(BOARD_SIZE);
		int tY = r.nextInt(BOARD_SIZE);
		//User input
		Scanner keyboard = new Scanner(System.in);
		//Set up the board
		Spaces[][] board = new Spaces[BOARD_SIZE][BOARD_SIZE];
		//Initialize the board
		for(int y=0;y<board.length;y++)
		{
			for(int x=0;x<board[y].length;x++)
			{
				board[x][y] = Spaces.Empty;
			}
		}
		//Put the user on the board
		board[pX][pY] = Spaces.Player;
		//Puts the goal on the board
		board[tX][tY] = Spaces.Goal;
		//puts the mines on the board
		board[tX][tY] = Spaces.mine;
		//Prompt the user
		System.out.println("Welcome to catch me where you have to catch the enemy");
		//Game over condition
		boolean gameOver = false;
 
		while(gameOver == false)
		{
			//Draw the board
			for(int y=0;y<board.length;y++)
			{
				for(int x=0;x<board[y].length;x++)
				{
					switch(board[x][y])
					{
					case Empty:
						System.out.print("_");
						break;
					case Player:
						System.out.print("X");
						break;
					case Walked_Path:
						System.out.print("#");
						break;
					case Goal:
						System.out.print("^");
						break;
					case mine:
						System.out.print("M");
					break;
					}
				}
				System.out.println(" ");
			}
			//Calculates the distance.  This doesn't use square root in order to save processing cycles
 
			//The player moves
			System.out.println("Enter either -1,0,1 to move in the x or 9 to quit");
			//Movement in the X direction
			int dX = keyboard.nextInt();
			//Or quit
			if(dX == 9)
			{
				System.out.println("Game over");
				break;
			}
 
			System.out.println("Enter either -1,0,1 to move in the y");
			//Movement in the y direction
			int dY = keyboard.nextInt();
 
			//Checks to see if the movement is valid
			if(dX <-1 || dX>1)
			{
				System.out.println("Invalid input X");
				dX = 0;
			}
			if(dY <-1 || dY>1)
			{
				System.out.println("Invalid input Y");
				dY = 0;
			}
 
			//Sets the player position to a walked path
			board[pX][pY] = Spaces.Walked_Path;
			//Moves the player
			pX+=dX;
			pY+=dY;
 
			//Makes sure everything is still in bounds
			if(pX < 0)
			{
				pX = 0;
			}
			else if(pX>BOARD_SIZE-1)
			{
				pX = BOARD_SIZE-1;
			}
			if(pY < 0)
			{
				pY = 0;
			}
			else if(pY> BOARD_SIZE-1)
			{
				pY = BOARD_SIZE-1;
			}
 
 
			//Winning condition
			if(board[pX][pY]==Spaces.mine)
			{
				System.out.println("You are dead!");
				break;
			}
			if(board[pX][pY]==Spaces.Goal)
			{
				System.out.println("You win! The secret location was at "+tX+" "+tY);
				System.out.println("It took "+numberOfMoves+" moves");
				gameOver = true;
			}
			//Sets the player in the new position
			board[pX][pY] = Spaces.Player;
			numberOfMoves++;
		}
	}
}

Since the mines occupy 1/10 of the board, I would expect the appropriate number of mines to be determined randomly and added to the game board when the board is first created. I don't see where you've determined more than one mine.

Give your variables better names: I'm not sure what pX/pY, tX/tY, etc. are supposed to be. NAME them.

sorry i know my variables are a bit confusing but would i just have to randomize the number of mines? would i have to create a public static final int of 10? since the board is 10 by 10

Assuming the program is not required to be scalable, set the variable to a constant, whatever you wish. But if there's any chance the size of the game board will change, then calculate the number of mines based on the game board's size. Then when you build the game board, assign that number of locations randomly to mines. Choosing those locations in a grid without repeating will be an interesting exercise. Any ideas?

hmm im thinking....how would i assign the number of locations randomly to mines? thats what im having trouble with haha

Random (Java Platform SE 6)

Produce random numbers, then assign the variables returned as you see fit.

Originally Posted by HappyCamper

hmm im thinking....how would i assign the number of locations randomly to mines? thats what im having trouble with haha

For this specific game, there are a hundred locations, so you could randomly generate 10 unique numbers from 0 - 99 and then determine how to assign those numbers to locations on the game board. If you think about the for() loops used to iterate a 2D array, it might occur to you that there's a way to calculate a number in the range 0 - 99 from each game board's location using the row/column values for each.