PHP implementation for 'Exponentiation by Squaring' method for finding power of a given number. This algorithm runs in O(log(P)) time where P is the power.

power.php

function findPower($base, $exponent){
	if($exponent==0) return 1;
	
	$output=$base;
	$p=1;
	
	while($p*2<$exponent){
		$output*=$output;
		$p+=$p;
	}

	return $output*findPower($base, $exponent-$p);
}