A selection of basic sorting algorithms in Ruby

Sorting Algorithms

module SortAlgorithms
  def self.benchmark(iterations, method, array)
    start_time = Time.now
    iterations.times { |i| method.call(array.clone) }
    Time.now - start_time
  end
 
  def self.bubble_sort(array)
    array.each do |elem|
      (array.size - 1).times do |i|
        if array[i] > array[i + 1]
          array[i], array[i + 1] = array[i + 1], array[i]
        end
      end
    end
  end
 
  def self.selection_sort(array)
    (array.size - 1).times do |i|
      min = i
      (array.size - i).times do |j|
        min = i + j if array[i + j] < array[min]
      end
      array[i], array[min] = array[min], array[i]
    end
    array
  end
 
  def self.merge_sort(array)
    return array if array.size <= 1
 
    left = merge_sort(array[0...array.size / 2])
    right = merge_sort(array[array.size / 2...array.size])
 
    merge(left, right)
  end
  
  def self.quick_sort(array)
    return array if array.size <= 1
  
    pivot = array.sample
    
    left_partition = quick_sort(array.find_all { |x| x < pivot })
    right_partition = quick_sort(array.find_all { |x| x > pivot })
    
    left_partition + [pivot] + right_partition
  end
 
  private
 
  def self.merge(left, right)
    array = []
    until left.empty? || right.empty?
      array << if left[0] < right[0]
        left.shift
      else
        right.shift
      end
    end
    array + left + right
  end
end
 
 
 
ARRAY_SIZE = 10
 
random_array = ARRAY_SIZE.times.map { |i| rand(1000) }
best_array = (1..ARRAY_SIZE).to_a
worst_array = best_array.reverse