php 发奖

session_start();
// unset($_SESSION['reward']);die;//清已领取过的奖励
//保存已领取过的奖励
function rewarded($id = 0)
{
    $reward = isset($_SESSION['reward']) ? $_SESSION['reward'] : array();
    if ($id !== 0) {
        array_push($reward, $id);
        $_SESSION['reward'] = $reward;
    }
    return $reward;
}
// 奖品概率
function configPro()
{
    $configPro = array(
    1 => array('pro'=>0.05),
    2 => array('pro'=>0.2),
    3 => array('pro'=>0.3),
    4 => array('pro'=>0.4),
    5 => array('pro'=>0.05),
    );
    $num = 100;//总的权重，保证每个奖励能是整数
    $total = 0;//实际总权重
    $rewarded = rewarded();//已经领取过的奖励
    // 计算每个奖品的取值区间以及实际总权重
    foreach ($configPro as $key => &$val) {
        //排除掉已经发过的奖励（如果可以重复抽，注释掉此判断即可）
        if (in_array($key, $rewarded)) {
            unset($configPro[$key]);
            continue;
        }
        $val['min'] = $total+1;
        $weights = $num*$val['pro'];
        $total += $weights;
        $val['max'] = $total;
    }
    return array('total'=>$total, 'config'=> $configPro);
}

function giveReward()
{
    $data = configPro();
    if ($data['total'] == 0) {
        echo '已领完';die;
    }
    $rand = mt_rand(1, $data['total']);
    $id = 0;
    foreach ($data['config'] as $key => &$val) {
        if ($rand >= $val['min'] && $rand <= $val['max']) {
            $id = $key;
            rewarded($key);
            break;
        }
    }
    return $id;
}
var_dump('已领取奖励：',json_encode(rewarded()));
echo '<br/>';
$res = giveReward();
var_dump('当前领取奖励：', $res);