problem3.README

# Testing If a Number Is Prime

Factoring numbers is a popular and hugely important field in computer science.  In fact, the difficulty of factoring (large) numbers has been the main reason for the advancement of cryptography in the last 3 decades. If factoring were easier, then a lot of the Internet as we know it would not be secure, including logging into Facebook, GitHub, or making financial transactions.

We might look at factoring more later, but for this problem we will take a first step towards factoring, with a related problem. The goal is to test if a number is prime. Recall that a number is prime if the only numbers which divide it evenly are itself and 1. 0 and 1 are not prime. Specifically, your code will read in a single Int, and output a Bool if the number is prime, and false if it isn't.

To test if a number divides another number, you should know how to do this using modulo (remainder) operator: %.

The input integer will always be greater than or equal to 0. 

In addition, one of the test cases will be a significantly big number, and your program needs to run in under 5 seconds to get that test case correct. However, if you have difficulty achieving this, don't worry about it!

# Example Inputs and Outputs


Example input 1:
0

Example output 1:
false


Example input 2:
1

Example output 2:
false


Example input 3:
2

Example output 3:
true


Example input 4:
18

Example output 4:
false


Example input 5:
1000000007

Example output 5:
true