gmp_fact

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

gmp_factFattoriale

Descrizione

gmp_fact ( int $a ) : resource

Calcola il fattoriale (a!) di a.

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User Contributed Notes 2 notes

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0
raholl
1 year ago
I was expecting gmp_fact() is more effective than doing a while loop, but measurements show opposite:

<?php
$cislo
= 112;
$fact = $cislo;
$ffact = 1;
$mt = microtime();
while(
$fact >= 1)
{
   
$ffact = $fact * $ffact;
   
$fact--;
}
$md=number_format(microtime()-$mt, 6);
echo
"<h1>LOOP ($md):</h1>";
echo
$ffact;

$mt = microtime();
$vec = gmp_fact($cislo);
$md=number_format(microtime()-$mt, 6);
echo
"<h1>GMP FACT ($md):</h1>";
echo
$vec;
exit();
?>

WILL OUTPUT:

LOOP (0.000022s):
1.9745068572211E+182

GMP FACT (0.000132s):
1.9745068572211E+182

Result is 0.000022s loop, and 0.000132s gmp_fact()
up
-1
raholl
1 year ago
I was expecting gmp_fact() is more effective than doing a while loop, but measurements show opposite:

<?php
$cislo
= 112;
$fact = $cislo;
$ffact = 1;
$mt = microtime();
while(
$fact >= 1)
{
   
$ffact = $fact * $ffact;
   
$fact--;
}
$md=number_format(microtime()-$mt, 6);
echo
"<h1>LOOP ($md):</h1>";
echo
$ffact;

$mt = microtime();
$vec = gmp_fact($cislo);
$md=number_format(microtime()-$mt, 6);
echo
"<h1>GMP FACT ($md):</h1>";
echo
$vec;
exit();
?>

WILL OUTPUT:

LOOP (0.000022s):
1.9745068572211E+182

GMP FACT (0.000132s):
1.9745068572211E+182

Result is 0.000022s loop, and 0.000132s gmp_fact()
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