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@tomcha
Created December 20, 2014 07:22
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prime number ruby
#!/usr/bin/env ruby
# encoding: utf-8
def check_prime(num,array)
i = 0
sq_number = Math.sqrt(num).ceil.to_i
array.size.times do
if num % array[i] == 0
return false
else
break if(array[i] > sq_number)
i += 1
end
end
return array[-1]
end
start = Time.now.to_f
primenumbers = [2, 3]
# puts 2
# puts 3
num = 5
i = 1
while (i < 100000) do
if check_prime(num, primenumbers)
puts num
primenumbers.push(num)
end
num += 2
i += 1
end
endt = Time.now.to_f
puts ((endt - start)*1000).to_s + "ミリ秒"
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