$prime(N)

By NIGathan on Mar 06, 2009

I havent posted anything in a while, and I was thinking about prime numbers for some odd reason... So I decided to port the C/C++ primity function to mIRC.

You can find the original code here: http://docs.google.com/Doc?id=dgrmft6x_0htx3n3fh&hl=en

It should be 99.99% accurate.

Returns $true if N ($1) is a prime number, and $false if it is not.

alias prime {
  if ($1 !isnum 2-) return $false
  var %x 2, %y $floor($sqrt($1))
  while (%x <= %y) {
    if (!$calc($1 % %x)) && (%x != $1) break
    inc %x
  }
  if (%y == $calc(%x -1)) return $true
  return $false
}

Like Page Follow Author

Comments

Jonesy44 - Mar 07, 2009

np. forgot to rate. 7/10

Respond

NIGathan - Mar 06, 2009

Thanks :D

Respond

Jonesy44 - Mar 06, 2009

done! Lol, it's a neat script. and for the small numbers i checked, it worked well and pretty much an instant reply even though it was running 2 while loops

Respond

NIGathan - Mar 06, 2009

lol, I just updated it with a REAL working version, only to see your post, make sure you use it instead.. The old one isnt 100% accurate, it cant find prime numbers if the only factor is a prime number (above 10) squared.

However, the updated one is as close to 100% as you can get.

Respond

Jonesy44 - Mar 06, 2009

alias prime {
  if ($1 !isnum 2- && !$prop) { return 2* $!prime: error; $prime(N)[.up|down] }
  if ($istok(up down,$prop,32)) {
    var %x = $1 
    while (%x) {
      if ($prime.test(%x)) { return %x }
      else { $replace($prop,up,inc,down,dec) %x }
    }
  }
  else { return $prime.test($1) }
}
alias prime.test {
  if ($1 !isnum 2-) return $false
  var %x 2, %y $floor($sqrt($1))
  while (%x <= %y) {
    if (!$calc($1 % %x)) && (%x != $1) break
    inc %x
  }
  if (%y == $calc(%x -1)) return $true
  return $false
}

Got bored to i added a bit on..
$prime(N)[.up|down] - searches up or down for the next prime num. or just checks with no $prop

Respond