Calculate factorial for 999

Question

I got a problem to solve. I need write a PHP scipt to calculate a factorial for a number from 1 to 1000, what seems easy, by it also says that "but if it gives INF for 999, your algorithm is wrong". I'm confused.

See perhaps [Is there a BigInteger class for PHP?](https://stackoverflow.com/questions/4427020/is-there-a-biginteger-class-in-php) — lurker, Jun 26 '17 at 16:40
because the PHP couldn't handle the number with that much number of digits, — Shobi, Jun 26 '17 at 16:43

Prags · Answer 1 · 2017-06-26T19:37:46.133

2

There is function in php to do this

<?php

$fact = gmp_fact(999); // 999 * 998 * 997, ... etc
echo gmp_strval($fact)
?>

This returns the factorial , for reference http://php.net/manual/en/function.gmp-fact.php

edited Jun 26 '17 at 19:37

answered Jun 26 '17 at 16:52

Prags

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Calculate factorial for 999

1 Answers1