素数検索

prime.rb

def prime_number(n)
  sqrt = Math.sqrt(n)
  factor_number = (2..sqrt).any? { |num| n % num == 0 }
  unless factor_number || n == 1
    "#{n}は素数です"
  else
    "#{n}は素数ではない"
  end
end

prime_number(1000)

##双子素数検索

prime.rb


def twins_range_prime(numbers)
  prime_number = Proc.new { |number|
    sqrt = Math.sqrt(number)
    factor_number = (2..sqrt).any? { |num| number % num == 0 }
    unless factor_number || number == 1
      number
    end
    }
  array = []
  (1..numbers).each do |number|
    array << prime_number.call(number)
  end
  array.compact.each_cons(2).select{ |b, r| (r - b) == 2}
end

p twins_range_prime(1000)

##三つ子素数検索

prime.rb


def prime_triplet(numbers)
   prime_number = lambda { |number|
    sqrt = Math.sqrt(number)
    factor_number = (2..sqrt).any? { |num| number % num == 0 }
    unless factor_number || number == 1
      number
    end
    }

  array = []
  (1..numbers).each do |number|
    array << prime_number.call(number)
  end
  array.compact.each_cons(3).select{ |a, b, c| (b - a == 2 && c - a == 6) || (b - a == 4 && c - a == 6) }
end

p prime_triplet(1000)

##四つ子素数検索

prime.rb


def prime_quadruplet(numbers)
   prime_number = lambda { |number|
    sqrt = Math.sqrt(number)
    factor_number = (2..sqrt).any? { |num| number % num == 0 }
    unless factor_number || number == 1
      number
    end
    }

  array = []
  (1..numbers).each do |number|
    array << prime_number.call(number)
  end
  array.compact.each_cons(4).select{ |a, b, c, d| (b - a == 2 && c - a == 6 && d - a == 8) }
end

p prime_quadruplet(1000)

##メルセンヌ素数検索

prime.rb


def mersenne_number(multiplier)
  prime_number = proc { |number|
    sqrt = Math.sqrt(number)
    factor_number = (2..sqrt).any? { |num| number % num == 0 }
    unless factor_number || number == 1
      "2の#{multiplier}乗は#{number}で素数です"
    else
      "2の#{multiplier}乗は#{number}で素数ではありません"
    end
  }

  number = (2 ** multiplier - 1)
  prime_number.call(number)
end

(1..10).each do |a|
puts mersenne_number(a)
end