Java Tetris-遍歷雙數組

Question

我正在構建tetris，並嘗試實現一種方法，該方法可通過tile的grid [] []進行迭代並從底部開始檢查每行的每一列，然后逐步向上移動（圖如果我開始，則會更快從底部開始，因為這是需要清除大多數行的位置）。

我對此的理解是-為每個行創建一個double for循環，檢查該行中的所有列是否已滿（不為null）。 如果是這樣，我將實現一個清除方法（實際上是將當前行設置為上面的行）。 現在，我只是想輸出“ Full”。

我的System.out.println(grid[row][col] + ", " + row + ", " + col); check正確顯示它從底部開始，然后迭代每一列...但是if (grid[row][col] != null) { check似乎不停留在該行...

public void checkBottomFull() {
int columnsFilled = 0;
    //loops through rows only after each column has finished
    for(int row = grid.length-2; row > 0; row--) {
        //loops through all columns per row, then row decrements
        for(int col = 0; col < grid[row].length; col++) {
            System.out.println(grid[row][col] + ", " + row + ", " + col);       
            if (grid[row][col] != null) {
                columnsFilled++;
                if (columnsFilled == grid.length-1) {
                    System.out.println("full");     
                }
            }
        }
    }
}

有什么想法嗎？

---

編輯

public void checkBottomFull() {
    for(int row = grid.length-1; row >= 0; row--) {
        //loops through columns of each individual row
        if (isFull(row)) {
            System.out.println("full");
            clearRow(row);      
        }
    }
}

public boolean isFull(int row) {
    for (int col = 0; col < grid[row].length-1; col++) {
         if(grid[row][col] == null) {
             System.out.println(grid[row][col] + "... " + row + ", " + col);
             return false;
         }
    }   
    return true;
}

public void clearRow(int row) {
    for (int col = 0; col < grid[row].length-1; col++) {
        System.out.println("clearing...");
        grid[row][col] = grid[row-1][col];
    }
}

System.out.println(grid[row][col] + "... " + row + ", " + col); 輸出：為什么列不遞增？

null... 9, 0
null... 8, 0
null... 7, 0
null... 6, 0
null... 5, 0
null... 4, 0
null... 3, 0
null... 2, 0
null... 1, 0
null... 0, 0

Answer 1

這里的幾個問題：

1. 您應該將int columnsFilled = 0移到外部for循環內，因為它僅是對當前行的檢查。 現在，經過第一行后，計數將不正確。
2. 您正在檢查if (columnsFilled == grid.length-1)實際上應該是if (columnsFilled == grid[row].length-1) 。 您的檢查將填充的列數與行數進行比較，而不是與給定行中的列數進行比較。

Answer 2

您可以考慮添加類似於以下內容的便利功能

public boolean isFullRow(Tile[][] grid, int row)
{
    for(int i=0; i<grid[row].length; i++)
    {
        if(grid[row][i] == null){ return false; }
    }
    return true;
}

這將有助於調試您的代碼，並使其（略微但不明顯）更快。

然后，您的checkButtomFull()函數可能看起來像

public void checkBottomFull() {
    //loops through rows only after each column has finished
    for(int row = grid.length-2; row > 0; row--) {
        if(isFullRow(grid, row)){
            // Do something if full row
        }
    }
}

最后，作為次要點，我的猜測是

for(int row = grid.length-2; row > 0; row--)

可以/應該寫成

for(int row = grid.length-1; row >= 0; row--) {

Answer 3

您發布的代碼中存在一些邏輯錯誤，附件的代碼修復了這些錯誤，而沒有為您實現所有功能。

public class SampleClass {

static String[][] grid = new String[4][10];

/**
 * @param args
 */
public static void main(String[] args) {
    // TODO Auto-generated method stub
    loadGrid();
    checkBottomFull();
}
public static void checkBottomFull() {
    int columnsFilled = 0;
    //loops through rows only after each column has finished
    for(int row = grid.length-1; row >= 0; row--) {//needed 'greater than or equal to'
        columnsFilled=0; //need to reinitialize this before every iteration
        for(int col = 0; col <= grid[row].length-1; col++) { //needed 'less than or equal to'
           System.out.println(row + ", " + col+", "+grid[row][col]);       
            if (grid[row][col] != null) {
                columnsFilled++;
            }
        }
        System.out.println("columns that have a character" + columnsFilled);
        System.out.println("Needs to be "+grid[row].length+" to remove row");
        if (columnsFilled == grid[row].length) {
            System.out.println("full");   //this is where you should remove a row  
        }
    }
}

private static void loadGrid() {
    grid[0] = new String[] {"X","X","X","X","X","X","X","X","X","X"};
    grid[1] = new String[] {"X","X",null,"X","X","X",null,"X","X","X"};
    grid[2] = new String[] {"X","X","X",null,"X","X",null,"X","X","X"};
    grid[3] = new String[] {"X","X",null,"X","X","X",null,"X","X","X"};
}

}

Answer 4

public static void checkBottomFull() {

    //loops through rows only after each column has finished
    for(int row = grid.length-1; row >= 0; row--) {
        //loops through all columns per row, then row decrements
        int columnsFilled = 0;
        for(int col = 0; col < grid[row].length; col++) {
            System.out.println(grid[row][col] + ", " + row + ", " + col);       
            if (grid[row][col] != null && ++columnsFilled == grid[row].length) {
                System.out.println("full");     
            }
        }
    }
}