Posts ID:257766 Favorites Creations
ID:257766

 ```//Title: Prime Number Checker//Credit to: Xx Dark Wizard xX//Contributed by: Xx Dark Wizard xX/*This will check any number and will return 1 if it is aprime number and 0 otherwise.*/proc IsPrime(n) if(n % 2 == 0 && n != 2) // even number return 0 var/s = sqrt(n) // avoid constant checking since sqrt() is slow for(var/i = 3, i <= s, i+=2) if(n % i == 0) // it isn't prime return 0 return 1 // its a prime number///*//Testing code/sample implementationmob verb Check(n as num) if(IsPrime(n)) src << "[n] is a prime number" else src << "[n] is not a prime number"//*/ ```
 #1 Mar 20 2007, 5:49 pm Please follow the format, DarkWiz! I've had to go through and change quite a few of yours. If something doesn't conform to the format, it doesn't get protected under the licence and would probably just fall under standard copyright (i.e., undistributable).
I think Lummox JR posted a more efficient version of this somewhere. I'll search for it.

Edit:
 ```proc/IsPrime(n) var/p=3,psq=9 if(n>2 && !(n%2)) return 0 while(psq<=n) if(!(n%p)) return 0 psq+=4*p+4; p+=2 return 1 ```