# Prime Number Hunter

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The following code is an Implementation of the Sieve of Eratosthenes in PHP. It's purpose is to sieve the natural numbers and separate the primes from the composites.

```    function find_primes(\$number)
{
global \$primes;

\$nlist = array();
\$sqrt = ceil(sqrt(\$number));

\$nlist[] = 2;
\$nlist[] = 3;
for(\$i=5 ; \$i < \$number ; \$i=\$i+2)
{
if(\$i%3 != 0)
\$nlist[] = \$i;
}

for(\$i=2,\$divisor=5; \$divisor < \$sqrt ; \$i++) {
/*
* Remove non primes numbers from an array (\$nlist)
* Non prime numbers are identified by dividing with a known
* prime (the prime number in our array at \$index)
*/
\$count = count(\$nlist);
\$j = \$i*\$i;
\$nlist2 = array_slice(\$nlist,0,\$j);

for( ; \$j ```

This code is a memory hog. If you try it with large numbers you might see an error such as the following. If you do the solution is to use the ini_set function to increase the momory limit. Eg: ini_set('memory_limit','256M');

PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 35 bytes) in /home/raditha/euler.php on line 19