alg.rb

class BooleanArray
  attr_reader :length
  attr_reader :used_length

  def initialize(length)
    @length = length
    @used_length = 0
    @inner = Array.new((length - 1) / 8 + 1, 0)
  end

  private

  def get_byte_bit(index)
    return [index / 8, index % 8]
  end

  public

  # get(i)
  def [](index)
    raise IndexOutOfBoundsException.new(index, @length) if (index < 0 || index >= @used_length)
    byte, bit = get_byte_bit(index)
    return ((@inner[byte]) & (1 << bit)) != 0
  end

  # set(i, value)
  # always returns value
  def []=(index, value)
    raise IndexOutOfBoundsException.new(index, @length) if (index < 0 || index >= @length)
    raise BooleanExpectedException.new(value) unless value.instance_of?(TrueClass) || value.instance_of?(FalseClass)
    byte, bit = get_byte_bit(index)
    if value
      @inner[byte] |= 1 << bit
    else
      @inner[byte] &= 255 - (1 << bit)
    end
    @used_length = index + 1 if index >= @used_length
    return value
  end

  # find(value)
  # returns nil when value is not found
  def find(value)
    # TODO
    raise BooleanExpectedException.new(value) unless value.instance_of?(TrueClass) || value.instance_of?(FalseClass)

    @used_length.times do |i|
      if value
       return  ((@inner[] & (1 << i) != 0)

      else
       
      end
    end

  end