gistfile1.rb

  def find_submissions(course)
    @course_category_submissions = Hash.new([])
  	self.submissions.each do |submission|
  		cat = "#{submission.assignment.assignment_category.name}"
  		weight = submission.assignment.assignment_category.weight
  		@course_category_submissions[[cat, weight]] = []
  	end
  	self.submissions.each do |submission|
  		cat = "#{submission.assignment.assignment_category.name}"
  		weight = submission.assignment.assignment_category.weight
  	  @course_category_submissions[[cat, weight]] << submission if submission.assignment.course_id == course.id && submission.assignment.due_date < Date.today
  	end
  	@course_category_submissions
  end