}
$factor = 3;
$maxFactor = sqrt($n);
while ($n > 1 && $factor <= $maxFactor) {
if ($n % $factor == 0) {
$factorArray[$factor] = 1;
//echo "\t".$n."\t".$factor."\n";
$n = $n / $factor;
$lastFactor = $factor;
while ($n % $factor == 0) {
$factorArray[$factor] += 1;
//echo "\t".$n."\t".$factor."\n";
$n = $n / $factor;
}
$maxFactor = sqrt($n);
}
$factor = $factor + 2;
}
if ($n != 1) {
$lastFactor = $n;
$factorArray[$n] = 1;
}
return numberOfDivisors($factorArray);
}
$factors = $triangle = $i = $divisors = 0;
while ($divisors < 500) {
$i++;
$triangle += $i;
$divisors = factor($triangle);
echo $triangle . "\t" . $divisors . "\n";
}
* if the number is divisible by two, then it's not prime and it's no longer
* needed to check other even numbers
*/
if ($num % 2 == 0) {
return false;
}
/**
* Checks the odd numbers. If any of them is a factor, then it returns false.
* The sqrt can be an aproximation, hence just for the sake of
* security, one rounds it to the next highest integer value.
*/
for ($i = 3; $i <= ceil(sqrt($num)); $i = $i + 2) {
if ($num % $i == 0) {
return false;
}
}
return true;
}
$t = fgets($_fp);
for ($i = 0; $i < $t; $i++) {
$num = trim(fgets($_fp));
$fact_array = factor($num);
$fact_array = array_unique($fact_array);
$fact_array = array_filter($fact_array, 'isPrime');
if (count($fact_array) > 0) {
echo max($fact_array);
} else {
echo $num;
}
echo "\n";
}
