<?php
error_reporting(E_ALL | E_STRICT);
header('Content-Type: text/html; charset=utf-8');
set_time_limit(0);

function SoMeOnE_getProbability($probability)
{
    $rand = rand(1,100);
    $list = array();
    $start = 0;
    $end = 0;
    $i = 1;

    foreach ($probability as $k=>$item) {
        $end = $end + $item*100;
        for ($start; $start<=$end; $start++) {
            $list[$i]['number'][] = $start;
        }
        $list[$i]['key'] = $k;
        $start = $start - 1;
        $i++;
    }

    foreach ($list as $item) {
        if (in_array($rand, $item['number'])) {
            $result = $item['key'];
        }
    }

    return $result;
}

function alive_getProbability($array_in, $precisely = 100)
{
//
	$j=0;
	$result = 'event0';
    $n=$precisely*array_sum($array_in);
    $prob = rand(1,$n);

    foreach ($array_in as $k=>$item) 
        {
		    $j = $j + $precisely*$item;
			if($j >= $prob)
			{
			$result = $k;
			break;
			}
		}
return $result;
}

function twin_getProbability($array)
{
    $out = array();

    foreach($array as $k => $v)
    {
        $tmp = array_fill(0, $v * 100, $k);
        $out = array_merge($out, $tmp);
    }

    return $out[array_rand($out)];
}

function kirik_getProbability($array) {
    $rnd = rand(0, 100);
    $pv = 0;
    $ev = '';

    foreach($array as $k => $v) {
        $v *= 100;
        $ev = $k;
        if($rnd > $pv && $rnd <= $v + $pv) {
            break;
        }
        $pv += $v;
    }
    return  $ev;
}

function Invis1ble_getProbability($events)
{
    while (true)
    {
        $r = array_rand($events);
        if (mt_rand(1, 1000000) <= $events[$r] * 1000000)
            return $r;
    }
}

$programmers = array(/*'SoMeOnE',*/ 'alive', /*'twin',*/ 'kirik', 'Invis1ble');
$events = array('event1' => .5, 'event2' => .25, 'event3' => .2, 'event4' => .0425, 'event5' => .0075);
$iterate = 100000;
echo $iterate . ' итераций<br />';
foreach ($programmers as $programmer)
{
    echo '-----------------------------------------------------------------<br />';
    echo $programmer . '<br />';
    $funcName = $programmer . '_getProbability';
    $start = microtime(true);
    $stats = array();
    for ($i = 0; $i < $iterate; ++ $i)
    {
        $event = $funcName($events);
        $stats[$event] = isset($stats[$event]) ? $stats[$event] + 1 : 1;
    }
    echo sprintf('Время выполнения %.5f сек<br />', microtime(true) - $start);
    echo '<table style="font-size:14px"><tr><th>Событие</th><th>дано</th>&a mp;l t;th>результат</th><th>отклонение</th></tr>';
    foreach ($stats as $event => $cnt)
    {
        $proc = 100 * $cnt / $iterate;
        echo '<tr><td>' . $event . '</td>
              <td>' . ($events[$event] * 100) . '%</td>
              <td>' . $proc . '%</td>
              <td>' . ($proc / $events[$event] - 100) . '%</td></tr>';
    }
    echo '</table>';
}