#----------------------------------------------------------------------- # beckett.py #----------------------------------------------------------------------- import sys import stdio #----------------------------------------------------------------------- # Write to standard output Beckett's stage instructions to have n # actors enter (if parameter enter is True) or exit (if parameter # enter is False) the stage. def moves(n, enter): if n == 0: return moves(n-1, True) if enter: stdio.writeln('enter ' + str(n)) else: stdio.writeln('exit ' + str(n)) moves(n-1, False) #----------------------------------------------------------------------- # Accept integer n as a command-line argument. Write to standard # output Beckett's stage instructions (the bit positions that change # in a binary-reflected Gray code) for n actors. def main(): n = int(sys.argv[1]) moves(n, True) if __name__ == '__main__': main() #----------------------------------------------------------------------- # python beckett.py 1 # enter 1 # python beckett.py 2 # enter 1 # enter 2 # exit 1 # python beckett.py 3 # enter 1 # enter 2 # exit 1 # enter 3 # enter 1 # exit 2 # exit 1 # python beckett.py 4 # enter 1 # enter 2 # exit 1 # enter 3 # enter 1 # exit 2 # exit 1 # enter 4 # enter 1 # enter 2 # exit 1 # exit 3 # enter 1 # exit 2 # exit 1