CodeGym/Help with Java Tasks/First condition not met

Level 23

San Diego

05.09.2020
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6comments

First condition not met

Question about the task

Minesweeper (Part 9/16)

Games, Level 0, Lesson 0

Resolved

just need a little nudge. looks like it checks each neighbor and opens it but the verification doesn't like it.

According to the rules, when a cell without adjacent mines is revealed, the game reveals the "unmined" area up to cells with mined neighbors. Let's implement it... I suggest using recursion. It is used when the algorithm for solving the problem is the same as the algorithm for solving part of the problem. Here's what we have.

When a cell with zero mined neighbors is revealed, we need to do a full search of all neighboring cells that haven't been revealed, call openTile(int, int) method on them, and repeat the process.

Additionally, in the openTile(int, int) method, we'll arrange to display the number of mined neighbors of a cell.

Run the game to verify that the implementation is correct.

Hint: if you get a java.lang.StackOverflowError, it means that you're setting the isOpen flag too late.

Requirements:

In the openTile(int, int) method, if the element is not a mine and has no mined neighbors, the openTile(int, int) method must be called recursively on each neighbor that hasn't been revealed.
The openTile(int, int) method must call the getNeighbors(GameObject) method if the element is not a mine and has no mined neighbors.
In the openTile(int, int) method, if the element is not a mine and has at least one mined neighbor, the number of mined neighbors must be displayed on the playing field. Use the setCellNumber(int, int, int) method.
The openTile(int, int) method must not display anything if the element is not a mine and has no mined neighbors. Use an empty string.

package com.codegym.games.minesweeper; import com.codegym.engine.cell.Color; import com.codegym.engine.cell.Game; import java.util.ArrayList; import java.util.List; public class MinesweeperGame extends Game { private static final int SIDE = 9; private GameObject[][] gameField = new GameObject[SIDE][SIDE]; private int countMinesOnField; private static final String MINE = "\uD83D\uDCA3"; private static final String FLAG = "\uD83D\uDEA9"; private int countFlags = 0; @Override public void initialize() { setScreenSize(SIDE, SIDE); createGame(); } private void createGame() { for (int y = 0; y < SIDE; y++) { for (int x = 0; x < SIDE; x++) { boolean isMine = getRandomNumber(10) < 1; if (isMine) { countMinesOnField++; } gameField[y][x] = new GameObject(x, y, isMine); setCellColor(x, y, Color.BLUE); } } countMineNeighbors(); countFlags = countMinesOnField; } private List<GameObject> getNeighbors(GameObject gameObject) { List<GameObject> result = new ArrayList<>(); for (int y = gameObject.y - 1; y <= gameObject.y + 1; y++) { for (int x = gameObject.x - 1; x <= gameObject.x + 1; x++) { if (y < 0 || y >= SIDE) { continue; } if (x < 0 || x >= SIDE) { continue; } if (gameField[y][x] == gameObject) { continue; } result.add(gameField[y][x]); } } return result; } private void countMineNeighbors(){ for (int y = 0; y < SIDE; y++) { for (int x = 0; x < SIDE; x++) { if (gameField[y][x].isMine == false){ for (GameObject g : getNeighbors(gameField[y][x])){ if (g.isMine == true){ gameField[y][x].countMineNeighbors++; } } } } } } private void openTile(int x, int y){ if (gameField[y][x].isOpen = false){ gameField[y][x].isOpen = true; if (gameField[y][x].isMine){ setCellValue(x, y, MINE); setCellColor(x, y, Color.RED); } else if (gameField[y][x].isMine == false && gameField[y][x].countMineNeighbors == 0){ String s = ""; setCellNumber(x, y, Integer.parseInt(0+s)); setCellColor(x, y, Color.GREEN); for (GameObject g : getNeighbors(gameField[y][x])){ if (g.isOpen == false && g.isMine == false && g.countMineNeighbors == 0){ openTile(g.x, g.y); } } } else { setCellNumber(x, y, gameField[y][x].countMineNeighbors); setCellColor(x, y, Color.GREEN); } } } @Override public void onMouseLeftClick(int x, int y){ openTile(x, y); } }

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Rich

Level 23 , San Diego, United States

15 September 2020, 22:10

it's not accepting this... any other tips? if (thisField.isMine){ setCellValue(x, y, MINE); setCellColor(x, y, Color.RED); } if (!thisField.isMine && thisField.countMineNeighbors == 0){ String s = ""; setCellNumber(x, y, Integer.parseInt(0+s)); setCellColor(x, y, Color.GREEN); for (GameObject g : getNeighbors(thisField)){ if (!g.isOpen){ list.add(g);//comment out //openTile(g.x, g.y); } } for (GameObject o : list){//comment out openTile(o.x, o.y);//comment out } } if (!thisField.isMine && thisField.countMineNeighbors != 0){ setCellNumber(x, y, thisField.countMineNeighbors); setCellColor(x, y, Color.GREEN); }

Nouser

Level 36 , Germany

16 September 2020, 09:38

again with a little bit more code the structure:

GameObject thisField = gameField[y][x];
//leave the method if the tile is already open
if (thisField.isOpen) return;

if (thisField.isMine) {
    //do stuff if the tile is a mine
} else {
    //no mine, then open the tile
    thisField.isOpen = true;
    //and do all the stuff necessarry here

    if (thisField.countMineNeighbors != 0) {
        //there are mines next to this field
    } else {
         //get the neighbours
    }
}

the loop through the returned neighbours looks good. Here do the atm commented out recursive call

if (!g.isOpen) openTile(g.x, g.y);

to optimize readibilty somewhat you could replace g with neighbor

if (!neighbor.isOpen) openTile(neighbor.x, neighbor.y);

Rich

Level 23 , San Diego, United States

19 September 2020, 05:03

That about did it thank you. now it just doesn't want to accept the empty string for the last requirement. setCellNumber(x, y, "");

Nouser

Level 36 , Germany

19 September 2020, 05:32

For me it worked to put setCellValue(x, y, ""); as first method call in the last else block good luck ;)

Rich

Level 23 , San Diego, United States

19 September 2020, 21:24

thank you. i appreciate the help

Nouser

Level 36 , Germany

5 September 2020, 11:21

useful

first, to make it easier for the eye, you can do sth like this:

GameObject thisField = gameField[y][x];

Then I suggest to start with just the mine check

if (thisField.isMine) {

in the else clause (task requirement: if the element is not a mine) check for mined neighbours (task requirement: and has no mined neighbors) -->

if (thisField.countMineNeighbors == 0) {

Now the requirements tell us: the openTile(int, int) method must be called recursively on each neighbor that hasn't been revealed So you just call the getNeighbors() method (parameter of course thisField) and save the result in a list. Loop over the list and call the openTile method on each entry (if it's not already open, isOpen field of GameObject). I think that's it