퀵 소트와 이진 검색 php 프로그램

<?php
if ($N && $target && $MAX) {
	for ($i=0;$i<$N;$i++) {
		$number[$i] = rand(1,$MAX);
	}
	$now= time();
	QuickSort (0,$N-1);
	$delay = time()-$now;
	echo "정렬에 ".$delay."초 걸림<br>";
	for($i=0;$i<$N;$i++)
		echo "<div style='width:80px;float:left;'>".$i.":".$number[$i]."</div>";

	echo "<div style='clear:both'></div>".$target."이/가 존재하는지 ".$s."로 알아보면<br>";

	if ($s=='순차검색') echo SequentialSearch ($number,$target,$N);
	else echo BinarySearch ($number,$target,0,$N-1,0);
}
?>
<form method action=BinSearch.php>
	최대값은?
	<input type=text name=MAX>
	수열의 크기는?
	<input type=text name=N>
	검색할 숫자는?
	<input type=text name=target>
	검색방법은?
	<select name=s>
		<option>순차검색</option>
		<option>이진검색</option>
	</select>
	<input type=submit value='Go'>
</form>
<?	
// 순차 검색 함수 (Sequential Search)
function SequentialSearch ($list, $target, $N) {
	for($i=0;$i<$N;$i++){
		if ($list[$i]==$target) return $i."번째에 성공";
	}
	return $i."번째에 실패";
}
// 이진 검색 함수 (Binary Search)
function BinarySearch ($list, $target, $p, $q, $cnt) {
	$cnt++;
	if ($p<=$q) {
		$i = (int)(($p+$q)/2);
		echo "위치 ".$i." ";
		if ($list[$i]==$target) {echo "들을 훑은 후 ".$cnt."번만에 성공"; return;}
		else if ($target<$list[$i]) BinarySearch ($list, $target, $p, $i-1,$cnt);
		else BinarySearch($list, $target, $i+1, $q, $cnt);
	}
	else {echo "들을 훑은 후 ".$cnt."번만에 실패"; return;}

}

function QuickSort ($p,$q) {
	global $number;
	if ($p<$q) {
		$i=$p; $j=$q;
		$c = (int)(($i+$j)/2);
//		echo $c." ".$number[$c]." ";
		while ($i<$j) {
			if ($number[$i]>$number[$c]) {
				while ($number[$j]>$number[$c]){
					$j--;
				}
				if ($j==$c) $c=$i;
				$temp = $number[$i];
				$number[$i]=$number[$j];
				$number[$j]=$temp;
			}
			if ($i<$c) $i++;
			if ($number[$j]<$number[$c]) {
				while ($number[$i]<$number[$c]){
					$i++;
				}
				if ($i==$c) $c=$j;
				$temp = $number[$i];
				$number[$i]=$number[$j];
				$number[$j]=$temp;
			}
			if ($c<$j) $j--;

		}
		QuickSort($p,$c);
		QuickSort($c+1,$q);
	}
	else return;
}

?>