Java 康威人生游戲

Question

我的節目是康威人生游戲，規則是：

1. 任何少於兩個活鄰居的活細胞都會死亡，好像是由於人口不足造成的。
2. 任何有兩三個活鄰居的活細胞都可以活到下一代。
3. 任何有超過三個活鄰居的活細胞都會死亡，就像人口過剩一樣。
4. 任何只有三個活鄰居的死細胞都會變成活細胞，就像通過繁殖一樣。

我能夠在一行中檢查活着的鄰居我的問題是檢查列中的活着的鄰居，並在檢查列時查看下一代是生是死，下面的代碼演示了我得到的結果，其中 1 代表一個活細胞0代表死細胞。

public static int[][] nextGeneration(int inputGrid[][]) {
                int height = 10, width = 10;
                int[][] future = new int[height][width];     
    
    for (int x = 1; x < height - 1; x++) {
                    for (int y = 1; y < width - 1; y++) {
                        int aliveNeighbours = 0;
                        for (int i = -1; i <= 1; i++)
                            for (int j = -1; j <= 1; j++)
                                aliveNeighbours += inputGrid[x + i][y + j];
        
                        aliveNeighbours -= inputGrid[x][y];
                        if ((inputGrid[x][y] == 1) && (aliveNeighbours < 2))
                            future[x][y] = 0;
            
                            else if (((inputGrid[x][y] == 1) && ((aliveNeighbours ==2) || (aliveNeighbours ==3))))
                                future[x][y] = 1;
            
                            else if ((inputGrid[x][y] == 1) && (aliveNeighbours > 3))
                                future[x][y] = 0;
            
                            else if ((inputGrid[x][y] == 0) && (aliveNeighbours == 3))
                                future[x][y] = 1;
            
                            else
                                future[x][y] = inputGrid[x][y];
                        }
                    }
                    return future;
                }
            public static void main(String[] args) {
                    int[][] game = 
                           {{0, 0, 1, 1, 1, 0, 0, 0, 0, 0},
                            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
                            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
                            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
                            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
                            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
                            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
                            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
                            {0, 0, 0, 0, 0, 0, 0, 0, 1, 1},
                            {0, 0, 0, 0, 0, 0, 0, 0, 1, 0}
                    };
            
                    System.out.println(nextGeneration(game));
                }

我的結果是：

    {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 1, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 1, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
    };

但預期的結果應該是：

    {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 1, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 1, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 1}

我的結果中的單元格 10*10 應該是活的而不是死的

Answer 1

您的循環的主要缺陷之一是 Java arrays （像大多數）具有從零開始的索引。 但是，您的循環從 x 和 y 設置為 1 開始，因此您根本不處理第一行。 此外，您的循環條件在您處理最后一行之前停止。 此代碼更正了該錯誤：

public static int[][] nextGeneration(int inputGrid[][]) {
    int height = 10, width = 10;
    int[][] future = new int[height][width];

    // iterate over each row (start with 0 because an array index is 0 based)
    for (int x = 0; x < height; x++) {
        // iterate over each column (start with 0 as well)
        for (int y = 0; y < width; y++) {
            int aliveNeighbours = 0;
            int rowAbove = Math.max(x -1, 0); // the row above is x-1 but never less than 0 because that row doesn't exist
            int rowBelow = Math.min(x + 1, height - 1); // the row below is never greater than the last row in the array (height - 1)
            int colLeft = Math.max(y -1, 0); // go to the left one column, unless we are at the edge, then don't go past 0
            int colRight = Math.min(y + 1, width - 1); // ... continuing the same logic as above
            for (int rowToCheck = rowAbove; rowToCheck <= rowBelow; rowToCheck++)
                for (int colToCheck = colLeft; colToCheck <= colRight; colToCheck++)
                    aliveNeighbours += inputGrid[rowToCheck][colToCheck];

            // remove the cell being evaluated from the neighbors count
            aliveNeighbours -= inputGrid[x][y];

            // simplified logic to remove unnecessary conditions
            // any cell with three neighbors is alive (past value doesn't matter)
            if (aliveNeighbours == 3)
                future[x][y] = 1;
            // any cell with fewer than two live neighbors is dead (past value doesn't matter)
            else if (aliveNeighbours < 2)
                future[x][y] = 0;
            // any cell with more than three neighbors is dead (past value doesn't matter)
            else if (aliveNeighbours >= 4)
                future[x][y] = 0;
            // any cell with two neighbors remains in its present state (regardless of what the past value was)
            else if (aliveNeighbours == 2)
                future[x][y] = inputGrid[x][y];
            else
                throw new RuntimeException("Unhandled neighbor condition");
        }
    }
    return future;
}

public static void main(String[] args) {
    int[][] game =
            {{0, 0, 1, 1, 1, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0, 0, 0, 1, 1},
            {0, 0, 0, 0, 0, 0, 0, 0, 1, 0}
            };

    var nextGen = nextGeneration(game);

    for(var row : nextGen)
    {
        for(var cell : row)
        {
            System.out.print(cell);
        }
        System.out.println();
    }