Something is missing...

Question about the task

Minesweeper (Part 9/16)

Games, Level 0, Lesson 0

Under discussion

I can't pass the last condition, but so far, I think that everything is working as it should. Any ideas?

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; public class GameObject { public int x; public int y; public boolean isMine; public int countMineNeighbors; public boolean isOpen; public boolean isFlag; public GameObject(int newX, int newY, boolean setMine){ this.x = newX; this.y = newY; this.isMine = setMine; } }

Comments (2)

Popular
New
Old

You must be signed in to leave a comment

Guadalupe Gagnon

Level 37 , Tampa, United States

6 April 2021, 14:06

useful

I think nouser's suggestion about line 90 will solve this task for you. I have some tips though: When using recursion make sure to start your method with all the "base" cases. This means everything that should stop recursion from happening. In this task the base cases in relative order of importance would be : 1) The cell is already open 2) the cell is a flag (and should not be opened) 3) the cell is a mine 4) the cell has mines in its surroundings (countMineNeighbors != 0) If none of those conditions are true then open ALL of the neighbors. If coded correctly then those 4 points will stop unnecessary recursion from continuing endlessly. Also, try to use the 'return' keyword. This will end the method if reached. This will clean up your code so you don't need to indent unnecessarily: Instead of this:

if()
   if()
   else if()
     for()
else if()

Do this:

if() return; // if the cell is already open
if() return; // if the cell is a flag
if() return; // if the cell is a mine
if() return; // if the cell has mine neighbors

for() // if reached none of the above are true open all

Nouser

Level 36 , Germany

6 April 2021, 13:33

useful

the if clause in line 89 ends with a semicolon. I bet you didn't want that. But to be honest, that isn't the worst idea. Leave it and move line 90 between lines 87 and 88. Otherwise the first tile being not a mine with no mined neighbors won't get a setCellValue call