8queens.java

void DrawSquares( Graphics canvas )
{
	canvas.setColor(Color.BLACK);
	for( int nRow=0; nRow<NUMROWS; nRow++ )
	{
		for( int nCol=0; nCol<NUMCOLS; nCol++ )
		{
			canvas.drawRect( BOARDLEFT + nCol * SQUAREWIDTH,
				BOARDTOP + nRow * SQUAREHEIGHT, SQUAREWIDTH, SQUAREHEIGHT );
				
			if( m_nBoard[nRow][nCol] != 0 )
			{
				canvas.drawImage( m_imgQueen,
					BOARDLEFT + nCol * SQUAREWIDTH + 8, BOARDTOP + nRow * SQUAREHEIGHT + 6, null );
			}
		}
	}
}
	
void CheckColumns( Graphics canvas )
{
	// Check all columns
	for(  int nCol=0; nCol<NUMCOLS; nCol++ )
	{
		int nColCount = 0;
		for( int nRow=0; nRow<NUMROWS; nRow++ )
		{
			if( m_nBoard[nRow][nCol] != 0 )
			{
				nColCount++;
			}
		}
		if( nColCount > 1 )
		{
			canvas.drawLine( BOARDLEFT + nCol * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
				BOARDTOP + ( SQUAREHEIGHT / 2 ),	
				BOARDLEFT + nCol * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
				BOARDTOP + SQUAREHEIGHT * 7 + ( SQUAREHEIGHT / 2 ) );
				
			m_bClash = true;
		}
	}
}

void CheckRows( Graphics canvas )
{
	for(  int nRow=0; nRow<NUMROWS; nRow++ )
	{
		int nRowCount = 0;
		for( int nCol=0; nCol<NUMCOLS; nCol++ )
		{
			if( m_nBoard[nRow][nCol] != 0 )
			{
				nRowCount++;
			}
		}
		if( nRowCount > 1 )
		{
			canvas.drawLine( BOARDLEFT + ( SQUAREWIDTH / 2 ),
				BOARDTOP + nRow * SQUAREHEIGHT + ( SQUAREHEIGHT / 2 ),	
				BOARDLEFT + 7 * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
				BOARDTOP + nRow * SQUAREHEIGHT + ( SQUAREHEIGHT / 2 ) );
				
			m_bClash = true;
		}
	}
}
	
void CheckDiagonal1( Graphics canvas )
{
	// Check diagonal 1
	
	for( int nRow=NUMROWS-1; nRow>=0; nRow-- )
	{
		int nCol = 0;
			
		int nThisRow = nRow;
		int nThisCol = nCol;

		int nColCount = 0;
			
		while( nThisCol < NUMCOLS &&
			nThisRow < NUMROWS )
		{
			if( m_nBoard[nThisRow][nThisCol] != 0 )
			{
				nColCount++;
			}
			nThisCol++;
			nThisRow++;
		}
			
		if( nColCount > 1 )
		{
			canvas.drawLine( BOARDLEFT + nCol * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
					BOARDTOP + nRow * SQUAREHEIGHT + ( SQUAREHEIGHT / 2 ),	
					BOARDLEFT + ( nThisCol - 1 ) * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
					BOARDTOP + ( nThisRow - 1 ) * SQUAREHEIGHT + ( SQUAREHEIGHT / 2 ) );
				
			m_bClash = true;
		}
	}

	for( int nCol=1; nCol<NUMCOLS; nCol++)
	{
		int nRow = 0;
		
		int nThisRow = nRow;
		int nThisCol = nCol;

		int nColCount = 0;
			
		while( nThisCol < NUMCOLS &&
			nThisRow < NUMROWS )
		{
			if( m_nBoard[nThisRow][nThisCol] != 0 )
			{
				nColCount++;
			}
			nThisCol++;
			nThisRow++;
		}
			
		if( nColCount > 1 )
		{
			canvas.drawLine( BOARDLEFT + nCol * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
					BOARDTOP + nRow * SQUAREHEIGHT + ( SQUAREHEIGHT / 2 ),	
					BOARDLEFT + ( nThisCol - 1 ) * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
					BOARDTOP + ( nThisRow - 1 ) * SQUAREHEIGHT + ( SQUAREHEIGHT / 2 ) );
				
			m_bClash = true;
		}
	}
}
	
void CheckDiagonal2( Graphics canvas )
{
	// Check diagonal 2
		
	for( int nRow=NUMROWS-1; nRow>=0; nRow-- )
	{
		int nCol = NUMCOLS - 1;
			
		int nThisRow = nRow;
		int nThisCol = nCol;

		int nColCount = 0;
			
		while( nThisCol >= 0 &&
			nThisRow < NUMROWS )
		{
			if( m_nBoard[nThisRow][nThisCol] != 0 )
			{
				nColCount++;
			}
			nThisCol--;
			nThisRow++;
		}
			
		if( nColCount > 1 )
		{
			canvas.drawLine( BOARDLEFT + nCol * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
					BOARDTOP + nRow * SQUAREHEIGHT + ( SQUAREHEIGHT / 2 ),	
					BOARDLEFT + ( nThisCol + 1 ) * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
					BOARDTOP + ( nThisRow - 1 ) * SQUAREHEIGHT + ( SQUAREHEIGHT / 2 ) );
				
			m_bClash = true;
		}
	}

	for( int nCol=NUMCOLS-1; nCol>=0; nCol--)
	{
		int nRow = 0;
		
		int nThisRow = nRow;
		int nThisCol = nCol;

		int nColCount = 0;
			
		while( nThisCol >= 0 &&
			nThisRow < NUMROWS )
		{
			if( m_nBoard[nThisRow][nThisCol] != 0 )
			{
				nColCount++;
			}
			nThisCol--;
			nThisRow++;
		}
			
		if( nColCount > 1 )
		{
			canvas.drawLine( BOARDLEFT + nCol * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
					BOARDTOP + nRow * SQUAREHEIGHT + ( SQUAREHEIGHT / 2 ),	
					BOARDLEFT + ( nThisCol + 1 ) * SQUAREWIDTH + ( SQUAREWIDTH / 2 ),
					BOARDTOP + ( nThisRow - 1 ) * SQUAREHEIGHT + ( SQUAREHEIGHT / 2 ) );
				
			m_bClash = true;
		}
			
	}
}