|
|
|
|
Like this code?
Show the author your appreciation.
|
|
| |
This script uses Sieve of Erastothenes to find all the prime up to a number
|
<?php
//Made by Chao Xu
//http://webdevlogs.com/
function esprime($limit){
$sqrtlimit = sqrt($limit);
$range = 0;
while($range<$limit){
$i .= '11';
$range+=2;
}
$n = 2;
while($n < $sqrtlimit){
if ($i[$n]){
$sqn = $n*$n;
$k = $sqn;
$i[$k]=0;
while($k<=$limit){
$k += $n;
$i[$k]=0;
}
}
++$n;
}
$n = 1;
while($n<$limit){
if($i[$n]) $primes[] = $n;
$n+=2;
}
if($limit>=2) $primes[0] = 2;
return $primes;
}
?> | |
It returns an array of all prime number below an the argument.
| <?php
esprime(6);
//return array(2,3,5);
?> | | |
|
| Library of math functions to expand the functionality of PHP3. Version 1.2.1 fixes a major problem with the gcd function.
Categories : Algorithms, PHP, Math. | | | Diffusion-Limited Aggregation visualization Categories : PHP, Graphics, Algorithms, Math. | | | Reverse a given number Categories : PHP, Beginner Guides, Algorithms, Math. | | | Show the steps for converting a number from a given base to base 10. Shows the steps involved in converting a number from a given base to base 10. Categories : PHP, Math., Algorithms | | | How to judge if an integer is odd or is even in Php3? Categories : Math., PHP, Algorithms | | | Function to convert Arabic numbers into Roman Numerals Categories : Algorithms, PHP, Date Time | | | grab the result of any calculation you submit to the Google Calculator. Categories : PHP, Arrays, Web Services, Regexps, Math. | | | How to Generate a random 8 character string in php3? Categories : PHP, Algorithms | | | Credit Card Identification and Validation Class - The credit_card class provides methods for cleaning, validating and identifying the type of credit card numbers. Categories : PHP, PHP Classes, Credit Cards, Ecommerce, Algorithms | | | Boolean Keyword Interpreter Categories : PHP, Algorithms, Search Engines | | | Prime Spiral is a image plotted with all the primes in a number spiral.
Categories : Algorithms, Graphics, GD image library, Math. | | | Math operations on big numbers Categories : PHP, Math. | | | Latitude-Longitude to Miles Categories : PHP, Utilities, Math. | | | A recursive function to traverse a multi-dimensional array where the
dimensions are not known Categories : Arrays, PHP, Algorithms | | | what salt do I have to feed the crypt function with to make it work like the htpasswd command of apache? Categories : Algorithms, PHP, Authentication | |
|
|