红包实现方法

/**
 * 随机红包
 *
 * @param int $n 红包数
 * @param float $totalMoney 总钱数
 * @return array
 */
function hongBao($n, $totalMoney)
{
    if ($n > 100) {
        return '红包数大于100！';
    }
    $result = array();
    if ($n == 1) {
        array_push($result, number_format($totalMoney, 2));
    } else {
        //后缀小数位
        $suffixNumber = $totalMoney / $n < 0.1 ? 3 : 2;
        for ($i = 1; $i <= $n; $i++) {
            //随机系数
            $coefficient = lcg_value() + lcg_value();
            //最大系数
            $coefficient = $coefficient >= 1.70 ? 1.25 : $coefficient;
            //最后一次
            if ($i == $n) {
                //防止溢出
                if (array_sum($result) > $totalMoney) {
                    return hongBao($n, $totalMoney);
                    break;
                }
                $data = $totalMoney - array_sum($result);
            } else {
                $data = $coefficient * ($totalMoney / $n);
            }
            //防止等于0
            if (in_array(number_format($data, $suffixNumber), array(0.00, 0.000))) {
                $data += 0.01;
            }
            array_push($result, number_format($data, $suffixNumber));
        }
    }
    return $result;
}