Quicksort

Quicksort.php

<?php

function generateArray()
{
    $array = [];
    
    for ($i = 0; $i < 11; $i++) {
        $array[$i] = mt_rand(-100, 100);
    }
    
    return $array;
}


function quicksort($array) {
    if (count($array) == 0) return [];
 
    $pivot_element = $array[0];
    
    $left_element = $right_element = array();

    for ($i = 1; $i < count($array); $i++) {
        if ($array[$i] <$pivot_element)
            $left_element[] = $array[$i];
        else
            $right_element[] = $array[$i];
    }

    return array_merge(quicksort($left_element), array($pivot_element), quicksort($right_element));
}

$array = generateArray();

print_r($array);

$start = microtime(true);

$array = quicksort($array);

$time = (microtime(true) - $start) * 1000;

echo "\n\nExecuted in {$time} seconds\n\n";

echo "A billion times: ". (($time * 1000000000)/60/60)/24 ." days";

print_r($array);