</title>
<body>
<?php
function find_divisors($number)
{
$divisors = array();
$number_sqrt = sqrt($number);
for ($i = 1; $i <= $number_sqrt; $i++) {
if ($number % $i == 0) {
array_push($divisors, $i, $number / $i);
}
}
return $divisors;
}
function print_array($array)
{
for ($i = 0; $i < count($array) - 1; $i++) {
// you can use count or sizeof($array)
echo "{$array[$i]},";
}
echo $array[count($array) - 1];
}
$divs = find_divisors(720);
print_array($divs);
?>
</body>
</html>
<?php
$house = 1;
$max = 29000000 / 10;
function find_divisors($num)
{
$max = $num / 2;
// twice faster
$divisors = array($num);
// but we have to add one manually
for ($i = 1; $i <= $max; $i++) {
if ($num % $i == 0) {
$divisors[] = $i;
}
}
return $divisors;
}
$time_start = microtime(true);
do {
$current = array_sum(find_divisors($house));
//var_dump($current);print "<br/>";
$house++;
} while ($current <= $max);
print "<br/><br/>time: ";
$time_end = microtime(true);
print $time_end - $time_start . "<br/><br/>";
var_dump($current);
var_dump($house);
