Python

I need the pseudo-code of the following program:

import random

from tkinter import * from tkinter import ttk from tkinter.font import Font

#from demopanels import MsgPanel, SeeDismissPanel

class KnightsTourDemo(ttk.Frame): def __init__(self, isapp=True, name='knightstourdemo'): ttk.Frame.__init__(self, name=name) self.pack(expand=Y, fill=BOTH) self.master.title('Knights Tour Canvas Demo') self.isapp = isapp self._create_widgets() def _create_widgets(self): #if self.isapp: # message panel not required #SeeDismissPanel(self) self._create_demo_panel() def _create_demo_panel(self): demoPanel = Frame(self, name='demo') demoPanel.pack(side=TOP, fill=BOTH, expand=Y) board = self._create_tour(demoPanel) self._add_bindings(board) def _create_tour(self, parent): c = Canvas(parent, width=240, height=240, name='board') self._draw_board(c) txt = Text(parent, width=10, height=1, name='dlg', background='white', font=('Arial', 8)) vscroll = ttk.Scrollbar(parent, orient=VERTICAL, command=txt.yview) txt['yscrollcommand'] = vscroll.set controls = self._create_controls(parent, c)

# position and configure resize behaviour c.grid(row=0, column=0, sticky='news') txt.grid(row=0, column=1, sticky='news') vscroll.grid(row=0, column=2, sticky='news') controls.grid(row=1, column=0, columnspan=3, sticky=N+E) parent.rowconfigure(0, weight=1) parent.columnconfigure(1, weight=1) return c

def _draw_board(self, canvas): # draw checkerboard for r in range(7, -1, -1): for c in range(8): if c&1 ^ r&1: fill = 'tan3' dfill = 'tan4' else: fill = 'bisque' dfill= 'bisque3' coords = (c*30+4, r*30+4, c*30+30, r*30+30) canvas.create_rectangle(coords, fill=fill, disabledfill=dfill, width=2, state='disabled') # create knight canvas.create_text(0, 0, font=('Courier 20'), text='\u265e', anchor='nw', tags='knight', fill='black', activefill='#600000') # randomly place him on the board self._put_random_knight(canvas) def _create_controls(self, parent, canvas): # board controls delay = IntVar() continuous = BooleanVar() frame = ttk.Frame(parent, name='controls') ttk.Label(frame, text='Speed').pack(side=RIGHT, padx=(4,24), pady=12) ttk.Scale(frame, from_=8, to=2000, variable=delay).pack(side=RIGHT, padx=4, pady=12) ttk.Checkbutton(frame, text='Repeat', variable=continuous).pack(side=RIGHT, padx=4, pady=12) btn = ttk.Button(frame, text='Start', name='start') btn['command'] = self._start_tour btn.pack(side=RIGHT, padx=(16,4), pady=12)

# set variable values and safe a reference to them delay.set(600) continuous.set(False) canvas.__delay = delay canvas.__continuous = continuous return frame # ======================================================================== # Bindings # ======================================================================== def _add_bindings(self, board): board.tag_bind('knight', '<1>', lambda e, b=board: self._start_drag(e, b)) board.tag_bind('knight', '', lambda e, b=board: self._drag(e,b)) board.tag_bind('knight', '', lambda e, b=board: self._end_drag(e,b)) # ======================================================================== # Bound methods # ======================================================================== def _start_drag(self, evt, board): # save drag start coords board.__lastX = board.canvasx(evt.x) board.__lastY = board.canvasy(evt.y) def _drag(self, evt, board): # move the knight with the mouse x = board.canvasx(evt.x) y = board.canvasy(evt.y) board.move(CURRENT, x-board.__lastX, y-board.__lastY) board.__lastX = x board.__lastY = y def _end_drag(self, evt, board): # place the knight in the square closest to # the mouse position square = board.find_closest(evt.x, evt.y, 0, 65) coords = board.coords(square) board.coords(CURRENT, (coords[0], coords[1]))

# ======================================================================== # Commands # ========================================================================

def _start_tour(self, square=None): # start a new Knight's Tour self._toggle_start_btn('disabled') b = self.nametowidget('demo.board') # board t = self.nametowidget('demo.dlg') # text t.delete(1.0, END) # clear text visited = [] # squares visited in this tour for n in range(64): b.itemconfigure(n, {'state': 'disabled', 'outline': 'black'}) if not square: # get start position from current placement of knight coords = b.coords('knight') square = b.find_closest(coords[0], coords[1], 0, 65)

if square[0] > 64: # knight is off the board self._put_random_knight(b) coords = b.coords('knight') square = b.find_closest(coords[0], coords[1], 0, 65) square = (square[0]-1, ) b.__initial = square # save starting square self._move_piece(b, t, square, square, visited)

# ======================================================================== # Chessboard methods # ======================================================================== def _toggle_start_btn(self, newState): sbtn = self.nametowidget('demo.controls.start') sbtn.configure(state=newState) def _put_random_knight(self, board): # randomly choose a board square and position # the knight sqr = int( 1 + random.random() * 64) coords = board.coords((sqr, )) board.coords('knight', (coords[0], coords[1])) def _move_piece(self, b, txt, last, square, visited): # b - chess board (canvas) # txt - text console # last - last square visited # square - current square # display the square moves using standard # chess nomenclature chessSqr = '{}. {} .. {} '.format(len(visited), self._chess_sqr(last), self._chess_sqr(square) ) txt.insert(END, chessSqr ) txt.see(END) # configure squares, move the knight and update visited squares b.itemconfigure(1+last[0], state='normal', outline='black') b.itemconfigure(1+square[0], state='normal', outline='red') coords = b.coords(1+square[0]) b.coords('knight', (coords[0], coords[1])) visited.append(square[0]) # get the next move next = self._next_square(square[0], visited) if next != -1: # new legal move, pause and then move the knight self.after(b.__delay.get(), self._move_piece, b, txt, square, (next,), visited) else: # no legal moves left if len(visited) == 64: if b.__initial == square: txt.insert(END, 'Closed tour! ') self._toggle_start_btn('normal') else: txt.insert(END, 'Success ') self._toggle_start_btn('normal') if b.__continuous.get(): self.after(b.__delay.get() * 2, self._start_tour, self._put_random_knight(b)) else: txt.insert(END, 'Failed! ') self._toggle_start_btn('normal') return def _chess_sqr(self, square): # Display a square number as a standard chess square notation. return '{}{}'.format(chr(97 + square[0]%8), square[0]//8 + 1) def _valid_moves(self, square): # Return a list of squares accessible from the given square moves = [] pairs = [(-1,-2), (-2,-1), (-2,1), (-1,2), (1,2), (2,1), (2,-1), (1,-2)] for p in pairs : col = (square % 8) + p[0] row = (square // 8) + p[1] if (-1 < row < 8) and (-1 < col < 8): moves.append(row * 8 + col) return moves def _check_squares(self, square, visited): # Return the number of available moves for this square moves = 0 for test in self._valid_moves(square): if test not in visited: moves += 1 return moves

def _next_square(self, square, visited): # Select the next square to move to. # Returns -1 if no valid moves left minimum = 9 nextSqr = -1 for t in self._valid_moves(square): if t not in visited: count = self._check_squares(t, visited) if count < minimum: minimum = count nextSqr = t elif count == minimum: nextSqr = self._edgemost(nextSqr, t) return nextSqr

def _edgemost(self, a, b): # Select the square nearest the edge of the board colA = 3 - int(abs(3.5 - (a % 8))) colB = 3 - int(abs(3.5 - (b % 8))) rowA = 3 - int(abs(3.5 - (a // 8))) rowB = 3 - int(abs(3.5 - (b // 8))) if (colA * rowA) < (colB * rowB): return a else: return b if __name__ == '__main__': KnightsTourDemo().mainloop()