抽中概率 php

<code><span><span><?php</span><span>/**
*@FileName rand.php   抽中红包概率测试
**/</span>
header(<span>"Content-type: text/html; charset=utf-8"</span>); 
<span>/**
* 抽奖
*<span> @param</span> int $total 1为百分百中奖  2为二分之一中奖率  3为三分之一中奖率  以此类推...
*/</span><span><span>function</span><span>getReward</span><span>(<span>$total</span>=<span>10</span>)</span>
{</span><span>if</span>(<span>$total</span> == <span>1</span>){
  <span>return</span><span>1</span>;
}
<span>$win1</span> = (<span>$total</span>-<span>1</span>)/<span>100</span>;
<span>$other</span> = (<span>$total</span>-<span>1</span>)-<span>$win1</span>;
<span>$return</span> = <span>array</span>();
<span>for</span> (<span>$i</span>=<span>0</span>;<span>$i</span><<span>$win1</span>;<span>$i</span>++)
{
<span>$return</span>[] = <span>1</span>;<span>//中奖</span>
}
<span>for</span> (<span>$n</span>=<span>0</span>;<span>$n</span><<span>$other</span>;<span>$n</span>++)
{
<span>$return</span>[] = <span>0</span>;<span>//不中奖</span>
}
<span>//print_r($return);</span>
shuffle(<span>$return</span>);<span>//把数组中的元素按随机顺序重新排序</span><span>return</span><span>$return</span>[array_rand(<span>$return</span>)];
}
<span>$data</span> = getReward();
<span>echo</span><span>$data</span>;<span>die</span>;

<span>?></span></span></code>