PHP | gmp_rootrem() Function

The gmp_rootrem() is a built-in function in PHP which is used to calculate the nth root of a GMP number (GNU Multiple Precision : For large numbers) and returns the integer component of the nth root and its remainder .

Syntax :

gmp_rootrem($num,$n)

Parameters : This function accepts two mandatory parameters as shown in the above syntax. They are specified below :

• $num : The parameter can be a GMP object in PHP version 5.6 and later, or we can also pass a numeric string provided that it is possible to convert that string to a number.
• $n : The positive root to be calculated of $num.

Examples :

Input : $num = "8" $n = 2
Output :  Array ( 
                    [0] => GMP Object ( [num] => 2 )
                    [1] => GMP Object ( [num] => 4 )
                   )

Input : $num = "9" $n = 2
Output : Array ( 
                  [0] => GMP Object ( [num] => 3 )
                  [1] => GMP Object ( [num] => 0 ) 
              )

Return Value : This function returns a two element array , both the elements being GMP numbers.

• The first element of the array is the integer component of the nth root of $num.
• The second element is the remainder.

Below programs will illustrate the use of gmp_rootrem() function in PHP :

Program 1 : The below program illustrates the use of the function with GMP number passed as argument.

<?php
// PHP program to calculate the
// integer part and remainder
// of nth root of a gmp number

// GMP number as arguments
$num = gmp_init(8);
$n = 3;

$rootrem = gmp_rootrem($num, $n);

//Display the array elements
echo print_r($rootrem);
?>

Output

Array
(
    [0] => GMP Object ( [num] => 2 )
    [1] => GMP Object ( [num] => 0 )
)

Program 2 : The below program illustrates the use of the function with numeric string passed as argument.

<?php
// PHP program to calculate the
// integer part and remainder
// of nth root of a gmp number

// Numeric string as argument
$num = "178924890";
$n = 3;

$rootrem = gmp_rootrem($num, $n);

//Display the array elements
echo print_r($rootrem);
?>

Output

Array (
 [0] => GMP Object ( [num] => 563 ) 
[1] => GMP Object ( [num] => 471343 )  
)

Reference : http://php.net/manual/en/function.gmp-rootrem.php