首页 / 网页编程 / PHP / php中如何计算抽奖的概率

<？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; } $prize_arr = array（ "0" => array（"id"=>1,"prize"=>"1000000514","v"=>2）, "1" => array（"id"=>2,"prize"=>"1000000513","v"=>5）, "2" => array（"id"=>3,"prize"=>"1000000512","v"=>13）, "3" => array（"id"=>4,"prize"=>"1000000511","v"=>15）, "4" => array（"id"=>5,"prize"=>"1000000510","v"=>25）, "5" => array（"id"=>6,"prize"=>"1000000509","v"=>30）,"6" => array（"id"=>7,"prize"=>"1000000508","v"=>10）, ）; foreach （$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）;？>