化州网站开发公司/百度关键词排名提升工具

网上流传的优化函数本人在使用的时候出现问题，做了一点改动，把原来的一个函数拆成两个，即 intersect()和 intersect_sub().

看下面的代码：

$rand = function() {

$result = array();

for ($i = 0; $i < 100; null) {

$value = mt_rand(1, 10000);

if (!isset($result[$value])) {

$result[$value] = null;

$i++;

}

}

return array_keys($result);

};

$param_a = $rand();

$param_b = $rand();

$time = microtime(true);

$result = intersect($param_a, $param_b);

$time = microtime(true) - $time;

echo "intersect: {$time}
";

$time = microtime(true);

$result = array_intersect($param_a, $param_b);

$time = microtime(true) - $time;

echo "array_intersect: {$time}\n";

function intersect() {

if (func_num_args() < 2) {

trigger_error('param error', E_USER_ERROR);

}

$args = func_get_args();

foreach ($args AS $arg) {

if (!is_array($arg)) {

trigger_error('param error', E_USER_ERROR);

}

}

$result = array_shift($args);

sort($result);

foreach ($args as $arg) {

sort($arg);

$result = intersect_sub($result, $arg);

}

return $result;

}

function intersect_sub($a, $b) {

$result = array();

$length_a = count($a);

$length_b = count($b);

for ($i = 0, $j = 0; $i < $length_a && $j < $length_b; null) {

if($a[$i] < $b[$j]) {

$i++;

} else if($a[$i] > $b[$j]) {

$j++;

} else {

$result[] = $a[$i];

$i++;

$j++;

}

}

return $result;

};

运行结果如下：

intersect: 0.0060269832611084

array_intersect: 0.029041051864624从运行结果可以看出，优化后时间开销大约节省了4/5