方法一:
function get_rand($proArr) {
  $result = array();
  foreach ($proArr as $key => $val) {
    $arr[$key] = $val['v'];
  }
  // 概率数组的总概率
  $proSum = array_sum($arr);
  asort($arr);
  // 概率数组循环
  foreach ($arr as $k => $v) {
    $randNum = mt_rand(1, $proSum);
    if ($randNum <= $v) {
      $result = $proArr[$k];
      break;
    } else {
      $proSum -= $v;
    }
  }
  return $result;
} $arr = array(
  array('id'=>1,'name'=>'特等奖','v'=>1),
  array('id'=>2,'name'=>'一等奖','v'=>5),
  array('id'=>3,'name'=>'二等奖','v'=>10),
  array('id'=>4,'name'=>'三等奖','v'=>12),
  array('id'=>5,'name'=>'四等奖','v'=>22),
  array('id'=>6,'name'=>'没中奖','v'=>50)
); var_dump(get_rand($arr));

  

方法二:
function get_rand($proArr) {
$result = '';
//概率数组的总概率精度
$proSum = array_sum($proArr);
//概率数组循环
foreach ($proArr as $key => $proCur) {
$randNum = mt_rand(1, $proSum);
if ($randNum <= $proCur) {
$result = $key;
break;
} else {
$proSum -= $proCur;
}
}
unset($proArr);
return $result;
} $arr = array(
  array('id'=>1,'name'=>'特等奖','v'=>1),
  array('id'=>2,'name'=>'一等奖','v'=>5),
  array('id'=>3,'name'=>'二等奖','v'=>10),
  array('id'=>4,'name'=>'三等奖','v'=>12),
  array('id'=>5,'name'=>'四等奖','v'=>22),
  array('id'=>6,'name'=>'没中奖','v'=>50)
); foreach ($arr as $val) {
$item[$val['id']] = $val['v'];
} var_dump(get_rand($item));

  

php抽奖概率算法-LMLPHP

05-11 11:13
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