I have an array containing several students. I want them to cross-grade one another randomly, i.e. each student will grade someone and will be graded by someone else (these two people may or may not be the same person).

Here is my working solution. I'm sure there is a more elegant answer!

def randomize(student_array)
  graders = student_array.dup
  gradees = student_array.dup
  result = {}
  graders.each do |grader|
    gradee = grader
    while gradee == grader
      gradee = gradees.sample
    end
    result[grader] = gradee
    gradees.delete_at(gradees.index(gradee))
  end
  return result
end