extra課題(google)

!Mac OS X-10.15.7 !ruby-2.6.3p62

課題内容

自然対数の底e(200桁まで)の値で連続10桁で最初の素数を求める.以下をexp.txtとして入力として使用する．

2.71828182845904523536028747135266249775
7247093699959574966967627724076630353547
5945713821785251664274274663919320030599
2181741359662904357290033429526059563073
81323286279434907632338298807531952510190

方針

素数を特定するために, 以下サイトを参考にした.https://qiita.com/evendemiaire/items/f7069a77b7432a3622a3

コード

# require './aeroc'
require 'prime'
require 'colorize'


def puts_vals(expected, result)
    puts "expected :: #{expected}"
    puts "result   :: #{result}"
end


def assert_equal(expected, result)
    puts_vals(expected, result)
    print  case expected == result
	when true  ; "succeeded in #{__method__}.\n".green
	when false ; "failed in #{__method__}.\n".red
	end
end


def check(num)
    2.step(to: Math.sqrt(num), by: 1) do |i|    
    return false if num%i==0
    true
    end
end


def read_exp(path)
    exp = File.read(path).delete(".")
    return exp
  end


def exp_check(exp)
    0.step(to: exp.length-10, by: 1) do |i|
	num = exp[i..i+10-1].to_i
	if check(num)
	result = num
	end
	if Prime.prime?(num)
	assert_equal(num,result)
	break
	end
    end
end


if $PROGRAM_NAME == __FILE__
    exp = read_exp("exp.txt")
    exp_check(exp)
end

参考サイト

• https://qiita.com/daddygongon/items/ba94b0f2a73990fc6a07
• https://qiita.com/evendemiaire/items/f7069a77b7432a3622a3
• https://qiita.com/musutafakemaru/items/872870c52b170d510309

---

• source ~/my_ruby/grad_members_20f/members/drop-sd/lectures/ex_google.org