8 queen/game of life

[Frank Niessink]

root <root at sirius.ftsm.ukm.my> wrote:
> newbie question.

> 2. 8 non-attacking queen.

>    use backtracking. the function call itself back. how to do recursive call
>    in python? 

I used a Board class that can solve itself. The board keeps track of 
where the queens are.

class Board:
        """ Class implementing a chess board. """
        def __init__(self, size=8, display=None):
                self.size = size
                # board
                self.board = [0]*size*size
                # where are the queens
                self.queens = []
                # display is a class which supports putQueen, removeQueen
                # and a solved method
                self.display = display

	[snip...]

        def solve(self,col=0):
                if col >= self.size:
                        if self.display:
                                self.display.solved(self)
                        return
                for row in range(self.size):
                        if not self.putQueen(col, row):
                                continue
                        self.solve(col+1)
                        self.removeQueen(col, row)


Board.putQueen returns true if it can place a queen in the given
position, false otherwise.

If you want, I can mail you the complete program.

Cheers, Frank

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