GMP
PHP Manual

gmp_hamdist

(PHP 4 >= 4.0.4, PHP 5)

gmp_hamdist — Hamming distance

说明

int gmp_hamdist ( resource $a , resource $b )

Returns the hamming distance between a and b . Both operands should be non-negative.

参数

a

It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.

It should be positive.

b

It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.

It should be positive.

返回值

A GMP number resource.

范例

Example#1 gmp_hamdist() example

<?php
$ham1 = gmp_init("1001010011", 2);
$ham2 = gmp_init("1011111100", 2);
echo gmp_hamdist($ham1, $ham2) . "\n";

/* hamdist is equivilent to: */
echo gmp_popcount(gmp_xor($ham1, $ham2)) . "\n";
?>

上例将输出：

6
6

参见

GMP
PHP Manual