Java俄羅斯方塊 - 迭代通過雙數組

Question

我正在構建俄羅斯方塊，並試圖實現一種方法，它通過tile [] []迭代並檢查每行的每列，從底部開始，一直向上（figured如果我從底部開始，那麼這將是一個更快的檢查，因爲這是大多數行需要清除的地方）。

我對此的理解是 - 爲每一行創建一個double for循環，檢查該行中的所有列是否已滿（非空）。如果是，我會實現一個清晰的（這實際上是設置當前行=上面的行）。目前，我只是想輸出「Full」。

我System.out.println(grid[row][col] + ", " + row + ", " + col);檢查正確顯示，它開始在底行，然後再遍歷每個列...但if (grid[row][col] != null) {檢查似乎並沒有被留在該行...

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");  
       } 
      } 
     } 
    } 
} 

有什麼想法？

---

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：爲什麼不列遞增？

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

幾個問題在這裏：

1. 因爲它的假設是隻有當前排的檢查你應該將int columnsFilled = 0外爲內循環。就像現在一樣，在經過第一行之後，計數將不正確。
2. 您正在檢查if (columnsFilled == grid.length-1)，實際上這應該是if (columnsFilled == grid[row].length-1)。您的檢查將填充列的數量與行數進行比較，而不是針對給定行中的列數。

Answer 2

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");  
      } 
     } 
    } 
} 

Answer 3

，可以考慮添加類似的便利功能

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; 
} 

這將有助於調試代碼，以及使（略，但不顯着）更快。

然後你checkButtomFull()功能可能看起來像

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 
     } 
    } 
} 

最後，作爲一個小點，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 4

有在你發佈的代碼中有幾個邏輯錯誤，附加的代碼修正了它們而沒有實現everythi爲你。

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"}; 
} 

}