class PrimeArray
Public Class Methods
get_primes(num)
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# File lib/multiply_prime_numbers_table/prime_array.rb, line 5 def self.get_primes(num) time = Benchmark.measure { @primes_array = [] counter = 2 until @primes_array.size == num @primes_array << counter if counter.is_prime? # Avoid to check even numbers because only even prime number is 2 (counter+1).even? ? counter += 1 : counter +=1 end } # I add this report just to show illustrate how it gets exponentialy complex as it increases num puts "Time to takes to calculate first "+num.to_s+" prime numbers: " n = time.real Benchmark.bm(7) do |x| x.report("for:") { for i in 1..n; a = "1"; end } x.report("times:") { (n.to_i).times do ; a = "1"; end } x.report("upto:") { 1.upto(n) do ; a = "1"; end } end puts "\n" @primes_array end