# File app/controllers/nim_controller.rb, line 71
71:         def backspace
72:                 session[:sticks]=nil
73:           redirect_to :action => "first_time"
74:         end

    # File app/controllers/nim_controller.rb, line 23
23:   def extras
24:         @sticks=get_sticks
25:         @title="#{@sticks} sticks left"
26:         @user_choice=session[:user_choice]
27:         @computer_choice=session[:computer_choice]
28:         @displayed=get_displayed
29:         if @sticks == 0
30:                         session[:sticks]=nil
31:                 end
32:   end

   # File app/controllers/nim_controller.rb, line 2
2:   def first_time
3:         session[:user_choice]=nil
4:         session[:computer_choice]=nil
5:         session[:display]=nil
6:           redirect_to :action => "index"
7:   end

    # File app/controllers/nim_controller.rb, line 17
17:   def get_computer_choice
18:         session[:computer_choice] ||= 0
19:   end

    # File app/controllers/nim_controller.rb, line 11
11:   def get_sticks
12:         session[:sticks] ||= 7 + rand(10)
13:   end

    # File app/controllers/nim_controller.rb, line 8
 8:   def get_title
 9:                 'pick 1-3 sticks; pick the last one, and you lose'
10:         end

    # File app/controllers/nim_controller.rb, line 14
14:   def get_user_choice
15:         session[:user_choice] ||= 0
16:   end

    # File app/controllers/nim_controller.rb, line 33
33:   def selected(user_choice)
34:                 session[:user_choice] = user_choice.to_i
35:                 if session[:sticks] && (session[:user_choice] <= session[:sticks])
36:                         #we have a legal move
37:                         session[:sticks] -= session[:user_choice]
38:                         if session[:sticks]==0 #computer has won
39:                                         session[:displayed]=
40:                                         'remember, the computer and you take turns '+
41:                                         'to pick 1..3 sticks. If you pick the last '+
42:                                         'one, you lose, as you just did ;-)'
43:                                         session[:computer_choice]=nil
44: #                                       session[:choices]=nil
45:                         else #computer makes move
46:                                 session[:computer_choice]= (session[:sticks]-1) % 4
47:                                 #since 1,5,9,.. is a series of losing positions,
48:                                 #we try to get the opponent to one of them
49:                                 if session[:computer_choice] == 0
50:                                         #we are losing,
51:                                         #because sticks=4n+1, a losing position
52:                                         session[:computer_choice] = 1+ rand(3)
53:                                         #doesn't matter what we pick here, long as it
54:                                         #isn't more than the sticks available.
55:                                         if session[:computer_choice] >
56:                                                         session[:sticks]
57:                                                 session[:computer_choice] =
58:                                                         session[:sticks]
59:                                         end
60:                                 end
61:                                 session[:sticks] -= session[:computer_choice]
62:                                 if session[:sticks] == 0 #user has won
63:                                         session[:displayed] =  'you won!'
64: #                                       session[:choices]=[]
65:                                 else
66:                                 session[:displayed]=nil
67:                                 end
68:                         end
69:                 end
70:         end

    # File app/controllers/nim_controller.rb, line 20
20:   def start_choices
21:                 %w{1 2 3}
22:   end