Knight's tour c++
CodeGuru Home VC++ / MFC / C++ .NET / C# Visual Basic VB Forums Developer.com
Results 1 to 3 of 3

Thread: Knight's tour c++

  1. #1
    Join Date
    Sep 2011
    Posts
    3

    Unhappy Knight's tour c++

    Hey guys, I am trying to complete a c++ Knight's tour program. I am getting full output but the tour stops after the first move so my output is this

    00000000
    00000000
    00000000
    00000000
    00000000
    00000000
    00000000

    00000000
    00000200
    00000000
    00001000
    00000000
    00000000
    00000000
    00000000

    I think my problem is my if else statement cluster but I can't seem to determine what went wrong. I have a sneaking suspicion it has something to do with syntax. Here is my code.

    Code:
    #include <iostream>
    using namespace std;
    
    	const int rows = 8;
    	const int columns = 8;
    	void printArray( int[][columns]);
    
    
    int main ()
    {
    	int i, j;
    
    	int counter = 1;
    	int moveNumber = 1;
    	int currentRow = 3;
    	int currentColumn = 4;
    	int pastRow;
    	int pastColumn;
    
    	int chessBoard[rows][columns];
    
    	for (i = 0; i < 8; i++)
    	{
    		for (j = 0; j < 8; j++)
    		{
    			chessBoard[i][j] = 0;
    		}
    	}
    
    	printArray (chessBoard);
    	cout << endl;
    
    	chessBoard[currentRow][currentColumn] = counter;
    	counter++;
    
    	int horizontal [columns] = {2, 1, -1, -2, -2, -1, 1, 2};
    	int vertical [columns] = {-1, -2, -2, -1, 1, 2, 2, 1};
    
    	if (counter <= 64)
    	{
    		pastRow = currentRow;
    		pastColumn = currentColumn;
    		currentRow += vertical[moveNumber];
    		currentColumn += horizontal[moveNumber];
    
    		if ( chessBoard[currentRow][currentColumn] != 0)
    		{	currentRow = pastRow;
    			currentColumn = pastColumn;
    			moveNumber++;
    		}
    		else
    		{	chessBoard[currentRow][currentColumn] = counter;
    			counter++;
    			moveNumber = 1;
    		}
    	}
    
    		printArray (chessBoard);
    
    return 0;
    
    };
    
    void printArray( int a[rows][columns])
    {
    	for (int i = 0; i < rows; i++)
    	{
    		for (int j = 0; j < columns; j++)
    			cout << a[i][j] << ' ';
    			
    		cout << endl;
    	}
    }

  2. #2
    Join Date
    May 2009
    Posts
    2,413

    Re: Knight's tour c++

    Quote Originally Posted by Seeshi_suin View Post
    I think my problem is my if else statement cluster but I can't seem to determine what went wrong. I have a sneaking suspicion it has something to do with syntax.
    If it's a syntax problem the compiler will tell you and you're not going to be able to run the program at all.

    The program stops after it has done what it's instructed to do. You first assign a 1 to the 3,4 position. Then you assign a 1+1 to the 3-2, 4+1 position. That's it. You don't have a loop or a recursive call or anything that would continue the program, so it terminates.

  3. #3
    Join Date
    Feb 2007
    Posts
    20

    Re: Knight's tour c++

    Code:
    if (counter <= 64)
    As nuzzle pointed out, this accomplishes nothing. What you probably want instead is a terminating base condition of counter == 64, and a for-loop that calls the method recursively for each legal move from the current position of the knight. By legal move I mean a position that is not outside the bounds of the board, and that you haven't already visited. The skeleton of a solution looks like this:

    Code:
    if ( counter == 64 )
    {
        // done, print solution
        return;
    }
    
    for ( size_t i = 0;  i < 8;  ++i )
    {
        // compute newMoveRow by indexing into horizontal, adding value to currentRow
        // compute newMoveCol by indexing into vertical, adding value to currentCol
        if ( isLegalMove( board, newMoveRow, newMoveCol, i ) )
        {
            // record move on board: board[ newMoveRow, newMoveCol ] = count + 1
            // recursive call, pass as parameters board, nextMoveRow, nextMoveCol, counter+1
            // clear previous move: board[ newMoveRow, newMoveCol ] = 0
        }
    }

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


Azure Activities Information Page

Windows Mobile Development Center


Click Here to Expand Forum to Full Width

This is a CodeGuru survey question.


Featured


HTML5 Development Center