// Bing
preg_match_all('(<div class="sb_tlst">.*<h3>.*<a href="(.*)".*>(.*)</a>.*</h3>.*</div>)siU',$c_bing, $r_bing);

// Google
preg_match_all("@<h3\s*class=\"r\">\s*<a[^<>]*href=\"([^<>]*)\"[^<>]*>(.*)</a>\s*</h3>@siU",$c_google,$r_google);

// Yahoo
preg_match_all('(<h3><a class.*href="(.*)".*>(.*)</a>)siU',$c_yahoo,$r_yahoo);


$final_results = array();
$final_results_score = array();
$fcount = 0;

for ($i = 0; $i < count($r_bing[2]); $i++){
	// add all the bing results to the final results directly

	$final_results[$fcount] = $r_bing[1];
	$final_results_score[$fcount] = (10-$i); // more score more priority, so the rank 1 has 10 score
	$fcount++;
}

for ($i = 0; $i < count($r_google[2]); $i++){
	// now while adding google results check if the result already exist in the final_results
	for($j = 0; $j < $fcount; $j++){
		if($final_results[$j] == $r_google[1]){
			// if already exist you need not re-add it, but increase its score
			$final_results_score[$j] += (10-$i);
		}
		else{
			// if not, just add it to the list
			$final_results[$fcount] = $r_google[1];
			$final_results_score[$fcount] = (10-$i); // more score more priority, so the rank 1 has 10 score
			$fcount++;
		}
	}
}
// the same procedure to the yahoo results
for ($i = 0; $i < count($r_yahoo[2]); $i++){

	for($j = 0; $j < $fcount; $j++){
		if($final_results[$j] == $r_yahoo[1]){
			$final_results_score[$j] += (10-$i);
		}
		else{
			// if not, just add it to the list
			$final_results[$fcount] = $r_yahoo[1];
			$final_results_score[$fcount] = (10-$i);
			$fcount++;
		}
	}
}

// now that you have all the results without repeatation and also their scores
// use bubble sort algorithm to arrange them in order and you are done!

for($i = 0;$i < $fcount;$i++){
	for($j = 0;$j < $i-1;$j++){
		if($final_results_score[$j] < final_results_score[$j+1]){
			// swap score
			$temp = $final_results_score[$j];
			$final_results_score[$j] = $final_results_score[$j+1];
			$final_results_score[$j+1] = $temp;
			// and swap search too
			$temp = $final_results[$j];
			$final_results[$j] = $final_results[$j+1];
			$final_results[$j+1] = $temp;
		}
	}
}