Java井字游戏错误

Question

按照特定的标准，我必须使用GridWorld制作一个正常运行的井字游戏。我已经完成了大部分课程，但有一种方法是我坚持不懈的。我不确定如何检查对角线或垂直线是否有赢者。以下是方法。

public String getWinner() 
{ 
    Grid<Piece> grid = getGrid(); 
    if(grid == null) 
    { 
     return "no winner"; 
    } 

    String winner = ""; 
    for (int r = 0; r<grid.getNumRows(); r++) 
    { 
     Piece row0 = grid.get(new Location(r,0)); 
     Piece row1 = grid.get(new Location(r,1)); 
     Piece row2 = grid.get(new Location(r,2)); 

     if(row0 == null || row1 == null || row2 == null) 
     { 
      continue; 
     } 

     if(row0.getName().equals(row1.getName()) && row0.getName().equals(row2.getName())) 
     { 
      winner = row0.getName()+ " wins horizontally!"; 
      break; 
     } 
    } 

    //check for vertical winner 

    //check for diagonal winner 


    if(isWorldFull() && winner.length() == 0) 
    { 
     winner = "cat's game - no winner!\n\n"; 
    } 
    else if(!isWorldFull() && winner.length() == 0) 
    { 
     winner = "no winner"; 
    } 

    return winner; 
} 

任何和所有的帮助将不胜感激。

Answer 1

// vertically 
for (int c = 0; r<grid.getNumCols(); c++) 
{ 
    Piece col0 = grid.get(new Location(0,c)); 
    Piece col1 = grid.get(new Location(1,c)); 
    Piece col2 = grid.get(new Location(2,c)); 

    if(col0 == null || col1 == null || col2 == null) 
    { 
     continue; 
    } 

    if(col0.getName().equals(col1.getName()) && col0.getName().equals(col2.getName())) 
    { 
     winner = col0.getName()+ " wins vertically!"; 
     break; 
    } 
} 

// diagonal 1 
for (int x = 0; r<grid.getNumRows(); x++) 
{ 
    Piece d0 = grid.get(new Location(x,x)); 
    Piece d1 = grid.get(new Location(x,x)); 
    Piece d2 = grid.get(new Location(x,x)); 

    if(d0 == null || d1 == null || d2 == null) 
    { 
     continue; 
    } 

    if(d0.getName().equals(d1.getName()) && d0.getName().equals(d2.getName())) 
    { 
     winner = d0.getName()+ " wins diagonally!"; 
     break; 
    } 
} 

// diagonal 2 
for (int x = 0; r<grid.getNumRows(); x++) 
{ 
    Piece d0 = grid.get(new Location(x,2-x)); 
    Piece d1 = grid.get(new Location(x,2-x)); 
    Piece d2 = grid.get(new Location(x,2-x)); 

    if(d0 == null || d1 == null || d2 == null) 
    { 
     continue; 
    } 

    if(d0.getName().equals(d1.getName()) && d0.getName().equals(d2.getName())) 
    { 
     winner = d0.getName()+ " wins diagonally!"; 
     break; 
    } 
} 

注意，你可以提取代码为三个单元（row0,1,2，col0,1,2，d0,1,2）比较成这样一个单独的方法：

boolean check3Pieces(Piece p0, Piece p1, Piece p2, String caption) { 
    if(p0 == null || p1 == null || p2 == null) 
    { 
     return false; 
    } 

    if(p0.getName().equals(p1.getName()) && p0.getName().equals(p2.getName())) 
    { 
     winner = p0.getName()+ " " + caption; 
     return true; 
    } 
    return false; 
}