抽獎概率算法

<?php
header("Content-Type: text/html; charset=UTF-8");
function dump($arr){
    echo '<pre>'.print_r($arr,TRUE).'</pre>';
}
/*概率算法
proArr array(100,200,300，400)
*/
function get_rand($proArr) { 
    $result = '';  
    $proSum = array_sum($proArr);   
    foreach ($proArr as $key => $proCur) { 
        $randNum = mt_rand(1, $proSum); 
        if ($randNum <= $proCur) { 
            $result = $key; 
            break; 
        } else { 
            $proSum -= $proCur; 
        }         
    } 
    unset ($proArr);  
    return $result; 
}
/*
獲取中獎
*/
function  get_prize(){
$prize_arr = array( 
    array('id'=>1,'prize'=>'平板電腦','v'=>1), 
    array('id'=>2,'prize'=>'數碼相機','v'=>1), 
    array('id'=>3,'prize'=>'音箱設備','v'=>1), 
   array('id'=>4,'prize'=>'4G優盤','v'=>1), 
   array('id'=>5,'prize'=>'10Q幣','v'=>1), 
   array('id'=>6,'prize'=>'下次沒准就能中哦','v'=>95), 
);
foreach ($prize_arr as $key => $val) { 
    $arr[$val['id']] = $val['v']; 
} 
$ridk = get_rand($arr); //根據概率獲取獎項id 
$res['yes'] = $prize_arr[$ridk-1]['prize']; //中獎項 
unset($prize_arr[$ridk-1]); //將中獎項從數組中剔除，剩下未中獎項 
shuffle($prize_arr); //打亂數組順序 
for($i=0;$i<count($prize_arr);$i++){ 
    $pr[] = $prize_arr[$i]['prize']; 
} 
$res['no'] = $pr;
return $res;
}
dump(get_prize());

博客園參考文章

github參考源碼