dojo softeam 1

nimm.rb

class Solver
 attr_reader :stones
 def initialize(heap=0)
   @win=false
   @stones=heap
 end
 def user_wins?
   @win
 end
 def play(take)
   if (take!=2 or @stones==2)
     @win=true
   end
  
   @stones -= take
   if @stones % 4 == 0
     @stones -=3
   else
     @stones -= 4-take
   end

   if @stones>=4
     @win=false
   end

 end

end

test_nimm.rb

require 'test/unit'
require 'shoulda'
require 'nimm'

class TestNimm < Test::Unit::TestCase
  context "a Nimm solver" do
    should "assert false" do
      assert !false
    end
    should "win when there are no stones" do
      nim = Solver.new(0)
      assert !nim.user_wins?
    end
    should "lose when there is one stone" do
      nim = Solver.new(1)
      nim.play(1)
      assert nim.user_wins? 
    end
    should "win when there are 4 stones and user takes 3" do
      nim = Solver.new(4)
      nim.play(3)
      assert !nim.user_wins?
    end
    should "lose when there are 5 stones and the players takes 1 twice" do
      nim = Solver.new(5)
      nim.play(1)
      nim.play(1)
      assert nim.user_wins?
    end
    should "win when there are 5 stones and the players takes 2 stones" do
      nim = Solver.new(5)
      nim.play(2)      
      assert !nim.user_wins?
    end
    should "lose when there are 2 stones and the players takes 2 stones" do
      nim = Solver.new(2)
      nim.play(2)      
      assert nim.user_wins?
    end
    should "show the number of remaining stones" do
      nim = Solver.new(4)
      assert_equal 4,nim.stones
    end
    should "show 0 stones when there are 4 stones and user takes 3" do
      nim= Solver.new(4)
      nim.play(3)
      assert_equal 0, nim.stones
    end
    should "show 1 stone when there are 5 stones and the players takes 1" do
      nim = Solver.new(5)
      nim.play(1)
      assert_equal 1, nim.stones
    end
    should "show 1 stone when there are 6 stones and the players takes 2" do
      nim = Solver.new(6)
      nim.play(2)
      assert_equal 1, nim.stones
    end
    should "not consider the user has won when there are 6 stones and the user takes one" do
      nim = Solver.new(6)
      nim.play(1)
      assert !nim.user_wins?
    end
  end
end

# nim = Nimm.new(10)
# nim.play(2) => nim.win? =false nim.heap=5
# nim.play(1) => nim.win? =false nim.heap=1
# nim.play(1) => nim.win? =true nim.heap=0
# assert nim.win?

# nim = Nimm.new(10)
# nim.play(1) => nim.win? =false nim.heap=8
# nim.play(3) => nim.win? =false nim.heap=4
# nim.play(2) => nim.win? =false nim.heap=0
# assert !nim.win?