php如何实现计算抽奖概率的算法实例分享

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这篇文章主要介绍了PHP编程实现计算抽奖概率算法,结合完整实例形式分析了php随机数运算相关操作技巧,需要的朋友可以参考下

本文实例讲述了PHP编程实现计算抽奖概率算法。分享给大家供大家参考，具体如下：

<?php
  //计算抽奖的概率
  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;
  }
  $prize_arr = array(
    '0' => array('id'=>1,'prize'=>'家电','v'=>2),
    '1' => array('id'=>2,'prize'=>'数码相机','v'=>5),
    '2' => array('id'=>3,'prize'=>'iPad','v'=>13),
    '3' => array('id'=>4,'prize'=>'LED显示器','v'=>15),
    '4' => array('id'=>5,'prize'=>'U盘','v'=>25),
    '5' => array('id'=>6,'prize'=>'键盘','v'=>30),
    '6' => array('id'=>7,'prize'=>'鼠标垫','v'=>10),
  );
  foreach ($prize_arr as $key => $val) {
    $arr[$val['id']] = $val['v'];
  }
  $rid = get_rand($arr);
  $res['yes'] = $prize_arr[$rid-1]['prize'];
  unset($prize_arr[$rid-1]);
  shuffle($prize_arr);
  $prize_arrcount = count($prize_arr);
  for($i=0;$i<$prize_arrcount;$i++){
    $pr[] = $prize_arr[$i]['prize'];
  }
  $res['no'] = $pr;
  //抽奖结果
  $ro = $res['yes'];
  print_r($ro);
?>

运行结果：

iPad

needmorefarm

手机如何用代码下载音频