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Generating Prime Numbers: Reloaded

seanolad profile image Sean ・1 min read

So This Again

After posting my previous post I got okay feedback, but there was a key problem. My method to getting prime numbers was wrong. So I decided to create an alternative method that I know is fool proof.

My working solution

So this solution is pretty simple so I'm sure that even beginners will understand(last time I wrote my code in c++, ruby, python, and js, this time only python).

The Code:

Takes user input and generates all the primes under it(including the number itself if it's prime)

How would you have done it?

Discussion (2)

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nam288 profile image
Nam H. Le

Some advice:

  1. Your is_prime function has O(n) complexity. You can test only divisors in range [2, sqrt(n)] because if n has any divisor in range [sqrt(n), n) so it also has another in range [2, sqrt(n)].
  2. You can use Sieve of Eratosthenes to solve your original problem. :)
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thorstenhirsch profile image
Thorsten Hirsch

Glad you've found the right approach. :-)

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