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1 # Animated Towers of Hanoi using Tk with optional bitmap file in |
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2 # background. |
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3 # |
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4 # Usage: tkhanoi [n [bitmapfile]] |
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5 # |
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6 # n is the number of pieces to animate; default is 4, maximum 15. |
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7 # |
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8 # The bitmap file can be any X11 bitmap file (look in |
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9 # /usr/include/X11/bitmaps for samples); it is displayed as the |
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10 # background of the animation. Default is no bitmap. |
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11 |
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12 # This uses Steen Lumholt's Tk interface |
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13 from Tkinter import * |
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14 |
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15 |
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16 # Basic Towers-of-Hanoi algorithm: move n pieces from a to b, using c |
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17 # as temporary. For each move, call report() |
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18 def hanoi(n, a, b, c, report): |
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19 if n <= 0: return |
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20 hanoi(n-1, a, c, b, report) |
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21 report(n, a, b) |
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22 hanoi(n-1, c, b, a, report) |
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23 |
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24 |
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25 # The graphical interface |
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26 class Tkhanoi: |
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27 |
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28 # Create our objects |
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29 def __init__(self, n, bitmap = None): |
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30 self.n = n |
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31 self.tk = tk = Tk() |
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32 self.canvas = c = Canvas(tk) |
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33 c.pack() |
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34 width, height = tk.getint(c['width']), tk.getint(c['height']) |
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35 |
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36 # Add background bitmap |
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37 if bitmap: |
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38 self.bitmap = c.create_bitmap(width/2, height/2, |
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39 bitmap=bitmap, |
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40 foreground='blue') |
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41 |
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42 # Generate pegs |
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43 pegwidth = 10 |
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44 pegheight = height/2 |
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45 pegdist = width/3 |
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46 x1, y1 = (pegdist-pegwidth)/2, height*1/3 |
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47 x2, y2 = x1+pegwidth, y1+pegheight |
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48 self.pegs = [] |
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49 p = c.create_rectangle(x1, y1, x2, y2, fill='black') |
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50 self.pegs.append(p) |
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51 x1, x2 = x1+pegdist, x2+pegdist |
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52 p = c.create_rectangle(x1, y1, x2, y2, fill='black') |
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53 self.pegs.append(p) |
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54 x1, x2 = x1+pegdist, x2+pegdist |
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55 p = c.create_rectangle(x1, y1, x2, y2, fill='black') |
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56 self.pegs.append(p) |
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57 self.tk.update() |
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58 |
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59 # Generate pieces |
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60 pieceheight = pegheight/16 |
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61 maxpiecewidth = pegdist*2/3 |
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62 minpiecewidth = 2*pegwidth |
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63 self.pegstate = [[], [], []] |
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64 self.pieces = {} |
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65 x1, y1 = (pegdist-maxpiecewidth)/2, y2-pieceheight-2 |
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66 x2, y2 = x1+maxpiecewidth, y1+pieceheight |
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67 dx = (maxpiecewidth-minpiecewidth) / (2*max(1, n-1)) |
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68 for i in range(n, 0, -1): |
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69 p = c.create_rectangle(x1, y1, x2, y2, fill='red') |
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70 self.pieces[i] = p |
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71 self.pegstate[0].append(i) |
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72 x1, x2 = x1 + dx, x2-dx |
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73 y1, y2 = y1 - pieceheight-2, y2-pieceheight-2 |
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74 self.tk.update() |
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75 self.tk.after(25) |
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76 |
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77 # Run -- never returns |
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78 def run(self): |
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79 while 1: |
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80 hanoi(self.n, 0, 1, 2, self.report) |
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81 hanoi(self.n, 1, 2, 0, self.report) |
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82 hanoi(self.n, 2, 0, 1, self.report) |
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83 hanoi(self.n, 0, 2, 1, self.report) |
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84 hanoi(self.n, 2, 1, 0, self.report) |
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85 hanoi(self.n, 1, 0, 2, self.report) |
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86 |
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87 # Reporting callback for the actual hanoi function |
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88 def report(self, i, a, b): |
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89 if self.pegstate[a][-1] != i: raise RuntimeError # Assertion |
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90 del self.pegstate[a][-1] |
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91 p = self.pieces[i] |
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92 c = self.canvas |
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93 |
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94 # Lift the piece above peg a |
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95 ax1, ay1, ax2, ay2 = c.bbox(self.pegs[a]) |
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96 while 1: |
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97 x1, y1, x2, y2 = c.bbox(p) |
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98 if y2 < ay1: break |
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99 c.move(p, 0, -1) |
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100 self.tk.update() |
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101 |
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102 # Move it towards peg b |
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103 bx1, by1, bx2, by2 = c.bbox(self.pegs[b]) |
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104 newcenter = (bx1+bx2)/2 |
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105 while 1: |
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106 x1, y1, x2, y2 = c.bbox(p) |
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107 center = (x1+x2)/2 |
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108 if center == newcenter: break |
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109 if center > newcenter: c.move(p, -1, 0) |
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110 else: c.move(p, 1, 0) |
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111 self.tk.update() |
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112 |
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113 # Move it down on top of the previous piece |
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114 pieceheight = y2-y1 |
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115 newbottom = by2 - pieceheight*len(self.pegstate[b]) - 2 |
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116 while 1: |
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117 x1, y1, x2, y2 = c.bbox(p) |
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118 if y2 >= newbottom: break |
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119 c.move(p, 0, 1) |
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120 self.tk.update() |
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121 |
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122 # Update peg state |
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123 self.pegstate[b].append(i) |
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124 |
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125 |
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126 # Main program |
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127 def main(): |
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128 import sys, string |
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129 |
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130 # First argument is number of pegs, default 4 |
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131 if sys.argv[1:]: |
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132 n = string.atoi(sys.argv[1]) |
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133 else: |
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134 n = 4 |
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135 |
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136 # Second argument is bitmap file, default none |
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137 if sys.argv[2:]: |
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138 bitmap = sys.argv[2] |
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139 # Reverse meaning of leading '@' compared to Tk |
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140 if bitmap[0] == '@': bitmap = bitmap[1:] |
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141 else: bitmap = '@' + bitmap |
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142 else: |
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143 bitmap = None |
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144 |
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145 # Create the graphical objects... |
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146 h = Tkhanoi(n, bitmap) |
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147 |
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148 # ...and run! |
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149 h.run() |
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150 |
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151 |
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152 # Call main when run as script |
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153 if __name__ == '__main__': |
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154 main() |