# Prime Tester

cehsu
3,421 views

### Open Source Your Knowledge, Become a Contributor

Technology knowledge has to be shared and made accessible for free. Join the movement.

The goal today is to write a function that determines whether a number is prime.

## Check if a number is prime

Write an isPrime function that takes a number as parameter and returns true if this number is prime, false if it isn't.

Reminder: A prime number:

• Can only be divided by 1 and itself
• Is greater than 1
Write the isPrime function

## Optimize

Take a look at the Sieve of Eratosthenes. How much faster did your implementation of the sieve run? How can you account for this in terms of time complexity?

See:

https://github.com/AlgorithmsMeetup/GetAllPrimes

How about non-deterministic approaches?

See:

http://mathworld.wolfram.com/PrimalityTest.html

https://www.topcoder.com/community/data-science/data-science-tutorials/primality-testing-non-deterministic-algorithms/

Open Source Your Knowledge: become a Contributor and help others learn.