Problem 7 (written in Ruby)
def prime?(n)
return false if n % 2 == 0
lim = Math.sqrt(n).to_i
3.step(lim, 2) do |i|
return false if n % i == 0
end
return true
endprime_numbers = []
i = 2
while prime_numbers.size <= 10001
prime_numbers << i if prime?(i)
i += 1
endp prime_numbers.last
Problem:
http://odz.sakura.ne.jp/projecteuler/index.php?Problem%207
追記:<じゃなくて<=でした。(whileの条件)