Editing: hanoi.py
# Animated Towers of Hanoi using Tk with optional bitmap file in # background. # # Usage: tkhanoi [n [bitmapfile]] # # n is the number of pieces to animate; default is 4, maximum 15. # # The bitmap file can be any X11 bitmap file (look in # /usr/include/X11/bitmaps for samples); it is displayed as the # background of the animation. Default is no bitmap. # This uses Steen Lumholt's Tk interface from Tkinter import * # Basic Towers-of-Hanoi algorithm: move n pieces from a to b, using c # as temporary. For each move, call report() def hanoi(n, a, b, c, report): if n <= 0: return hanoi(n-1, a, c, b, report) report(n, a, b) hanoi(n-1, c, b, a, report) # The graphical interface class Tkhanoi: # Create our objects def __init__(self, n, bitmap = None): self.n = n self.tk = tk = Tk() self.canvas = c = Canvas(tk) c.pack() width, height = tk.getint(c['width']), tk.getint(c['height']) # Add background bitmap if bitmap: self.bitmap = c.create_bitmap(width//2, height//2, bitmap=bitmap, foreground='blue') # Generate pegs pegwidth = 10 pegheight = height//2 pegdist = width//3 x1, y1 = (pegdist-pegwidth)//2, height*1//3 x2, y2 = x1+pegwidth, y1+pegheight self.pegs = [] p = c.create_rectangle(x1, y1, x2, y2, fill='black') self.pegs.append(p) x1, x2 = x1+pegdist, x2+pegdist p = c.create_rectangle(x1, y1, x2, y2, fill='black') self.pegs.append(p) x1, x2 = x1+pegdist, x2+pegdist p = c.create_rectangle(x1, y1, x2, y2, fill='black') self.pegs.append(p) self.tk.update() # Generate pieces pieceheight = pegheight//16 maxpiecewidth = pegdist*2//3 minpiecewidth = 2*pegwidth self.pegstate = [[], [], []] self.pieces = {} x1, y1 = (pegdist-maxpiecewidth)//2, y2-pieceheight-2 x2, y2 = x1+maxpiecewidth, y1+pieceheight dx = (maxpiecewidth-minpiecewidth) // (2*max(1, n-1)) for i in range(n, 0, -1): p = c.create_rectangle(x1, y1, x2, y2, fill='red') self.pieces[i] = p self.pegstate[0].append(i) x1, x2 = x1 + dx, x2-dx y1, y2 = y1 - pieceheight-2, y2-pieceheight-2 self.tk.update() self.tk.after(25) # Run -- never returns def run(self): while 1: hanoi(self.n, 0, 1, 2, self.report) hanoi(self.n, 1, 2, 0, self.report) hanoi(self.n, 2, 0, 1, self.report) hanoi(self.n, 0, 2, 1, self.report) hanoi(self.n, 2, 1, 0, self.report) hanoi(self.n, 1, 0, 2, self.report) # Reporting callback for the actual hanoi function def report(self, i, a, b): if self.pegstate[a][-1] != i: raise RuntimeError # Assertion del self.pegstate[a][-1] p = self.pieces[i] c = self.canvas # Lift the piece above peg a ax1, ay1, ax2, ay2 = c.bbox(self.pegs[a]) while 1: x1, y1, x2, y2 = c.bbox(p) if y2 < ay1: break c.move(p, 0, -1) self.tk.update() # Move it towards peg b bx1, by1, bx2, by2 = c.bbox(self.pegs[b]) newcenter = (bx1+bx2)//2 while 1: x1, y1, x2, y2 = c.bbox(p) center = (x1+x2)//2 if center == newcenter: break if center > newcenter: c.move(p, -1, 0) else: c.move(p, 1, 0) self.tk.update() # Move it down on top of the previous piece pieceheight = y2-y1 newbottom = by2 - pieceheight*len(self.pegstate[b]) - 2 while 1: x1, y1, x2, y2 = c.bbox(p) if y2 >= newbottom: break c.move(p, 0, 1) self.tk.update() # Update peg state self.pegstate[b].append(i) # Main program def main(): import sys, string # First argument is number of pegs, default 4 if sys.argv[1:]: n = string.atoi(sys.argv[1]) else: n = 4 # Second argument is bitmap file, default none if sys.argv[2:]: bitmap = sys.argv[2] # Reverse meaning of leading '@' compared to Tk if bitmap[0] == '@': bitmap = bitmap[1:] else: bitmap = '@' + bitmap else: bitmap = None # Create the graphical objects... h = Tkhanoi(n, bitmap) # ...and run! h.run() # Call main when run as script if __name__ == '__main__': main()
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