Solution: Grades Histogram

nums = []

grades_file = File.expand_path File.join(File.dirname(__FILE__), "grades.txt")
grades_content = File.read(grades_file)
grades_content.split.each do |num|
  nums << num.to_i
end


range_array = []

min_number = 0
max_number = 100
(0..max_number).step(10).each do |num|
  next if min_number == num
  if num == max_number
    range_array << { :min => min_number, :max => num, :count => 0} # initialise
  else
    range_array << { :min => min_number, :max => num-1, :count => 0} # initialise
  end
  min_number = num
end

range_array.each do |entry|
  nums.each do |x|

    if x >= entry[:min] && x <= entry[:max]
      entry[:count] += 1
    end
  end
  puts "#{entry[:min].to_s.rjust(2)} - #{entry[:max].to_s.rjust(3)}: #{"*" * entry[:count]}"
end