康威的生命游戏（构造器和更新游戏）

Question

我接到了处理康威生命游戏的任务。

我的 CellGrid 方法和 simulateStep 方法有问题。存活概率似乎不起作用，在 simulateStep 中，我收到 NullPointerException 错误。

这是我的代码：

public class CellGrid
{
    private Cell[][] cells;


/**
 * This populates the grid with cells that will be
 * either living or dead (with this probability given by lifeChance)
 * 
 * @param size - grid size
 * @param lifeChance - probability of each cell starting out alive 
 */
public CellGrid(int size, double lifeChance)
{
    cells = new Cell[size][size];
    Random r = new Random();

    for (int i = 0; i < cells.length; i++)
    {
        for (int j = 0; j < cells.length; j++)
        {
            Cell c = new Cell();
            double nextVal = r.nextDouble();
            if (nextVal < lifeChance)
            {
                c.setAlive(false);
            }
            else
            {
                c.setAlive(true);
            }
        }
    }
}

/**
 * Iterates the simulation by one step (according to Game of Life rules)
 */
public void simulateStep()
{
    for (int y = 0; y < cells.length; y++)
    {
        for (int x = 0; x < cells.length; x++)
        {
            boolean living = cells[y][x].isAlive();
            int count = countNeighbours(y, x);
            boolean result = false;

            if (living && count <= 2)
            {
                result = false;
            }
            if (living && (count == 3 || count == 4))
            {
                result = true;
            }
            if (living && count == 5)
            {
                result = false;
            }
            if (living == true && count > 5)
            {
                result = true;
            }
            if (living == false && count > 5)
            {
                result = true;
            }

            result = cells[y][x].isAlive();
        }
    }
}

setAlive 方法：

public void setAlive(boolean alive)
{
    if (isAlive()== true)
    {
        this.alive = false;
    }

    if (isAlive() == false)
    {
        this.alive = true;
    }
}

感谢大家的帮助！

Answer 1

您应该在构造函数中将 Cell c = new Cell(); 更改为 cells[i][j] = new Cell();。

康威的生命游戏（构造器和更新游戏）

Conway's Game of Life (constructor and updating the game)

java

nullpointerexception

conways-game-of-life