Prime - 10万以下の素数を表示

example.rb

require 'benchmark'

Benchmark.bm( 8 ) do |reportor|

  reportor.report( "1000: " ) {
    primes = []
    1000.times do |x|
      x += 1
      if x != 1 and primes.all? { |y| x % y != 0 } then
        primes << x
        #p x
      end
    end
  }

  reportor.report( "10000:" ) {
    primes = []
    10000.times do |x|
      x += 1
      if x != 1 and primes.all? { |y| x % y != 0 } then
        primes << x
        #p x
      end
    end
  }

  reportor.report( "100000:" ) {
    primes = []
    100000.times do |x|
      x += 1
      if x != 1 and primes.all? { |y| x % y != 0 } then
        primes << x
        #p x
      end
    end
  }
end

           user     system      total        real

1000: 0.000000 0.000000 0.000000 ( 0.003194)
10000: 0.140000 0.000000 0.140000 ( 0.134306)
100000: 7.770000 0.000000 7.770000 ( 7.775869)

うげっｗ　コメント変ｗｗ

               user     system      total        real
1000:      0.000000   0.000000   0.000000 (  0.003194)
10000:     0.140000   0.000000   0.140000 (  0.134306)
100000:    7.770000   0.000000   7.770000 (  7.775869)