<?php
/**
* 随机红包+固定红包算法[策略模式]
* copyright (c) 2016 http://blog.csdn.net/CleverCode
*/
//配置传输数据DTO
class OptionDTO
{
//红包总金额
public $totalMoney;
//红包数量
public $num;
//范围开始
public $rangeStart;
//范围结算
public $rangeEnd;
//生成红包策略
public $builderStrategy;
//随机红包剩余规则
public $randFormatType; //Can_Left：不修数据,可以有剩余；No_Left：不能有剩余
public static function create(
$totalMoney,
$num,
$rangeStart,
$rangEnd,
$builderStrategy,
$randFormatType = 'No_Left'
) {
$self = new self();
$self->num = $num;
$self->rangeStart = $rangeStart;
$self->rangeEnd = $rangEnd;
$self->totalMoney = $totalMoney;
$self->builderStrategy = $builderStrategy;
$self->randFormatType = $randFormatType;
return $self;
}
}
//红包生成器接口
interface IBuilderStrategy
{
//创建红包
public function create();
//设置配置
public function setOption(OptionDTO $option);
//是否可以生成红包
public function isCanBuilder();
//生成红包函数
public function fx($x);
}
//固定等额红包策略
class EqualPackageStrategy implements IBuilderStrategy
{
//单个红包金额
public $oneMoney;
//数量
public $num;
public function __construct($option = null)
{
if ($option instanceof OptionDTO) {
$this->setOption($option);
}
}
public function setOption(OptionDTO $option)
{
$this->oneMoney = $option->rangeStart;
$this->num = $option->num;
}
public function create()
{
$data = [];
if (false == $this->isCanBuilder()) {
return $data;
}
$data = [];
if (false == is_int($this->num) || $this->num <= 0) {
return $data;
}
for ($i = 1; $i <= $this->num; $i++) {
$data[$i] = $this->fx($i);
}
return $data;
}
/**
* 等额红包的方程是一条直线
* @param mixed $x
* @return mixed
*/
public function fx($x)
{
return $this->oneMoney;
}
/**
* 是否能固定红包
* @return mixed
*/
public function isCanBuilder()
{
if (false == is_int($this->num) || $this->num <= 0) {
return false;
}
if (false == is_numeric($this->oneMoney) || $this->oneMoney <= 0) {
return false;
}
//单个红包小于1分
if ($this->oneMoney < 0.01) {
return false;
}
return true;
}
}
//随机红包策略(三角形)
class RandTrianglePackageStrategy implements IBuilderStrategy
{
//总额
public $totalMoney;
//红包数量
public $num;
//随机红包最小值
public $minMoney;
//随机红包最大值
public $maxMoney;
//修数据方式：NO_LEFT: 红包总额 = 预算总额；CAN_LEFT: 红包总额 <= 预算总额
public $formatType;
//预算剩余金额
public $leftMoney;
public function __construct($option = null)
{
if ($option instanceof OptionDTO) {
$this->setOption($option);
}
}
public function setOption(OptionDTO $option)
{
$this->totalMoney = $option->totalMoney;
$this->num = $option->num;
$this->formatType = $option->randFormatType;
$this->minMoney = $option->rangeStart;
$this->maxMoney = $option->rangeEnd;
$this->leftMoney = $this->totalMoney;
}
/**
* 创建随机红包
* @return mixed
*/
public function create()
{
$data = [];
if (false == $this->isCanBuilder()) {
return $data;
}
$leftMoney = $this->leftMoney;
for ($i = 1; $i <= $this->num; $i++) {
$data[$i] = $this->fx($i);
$leftMoney = $leftMoney - $data[$i];
}
//修数据
list($okLeftMoney, $okData) = $this->format($leftMoney, $data);
//随机排序
shuffle($okData);
$this->leftMoney = $okLeftMoney;
return $okData;
}
/**
* 是否能够发随机红包
* @return mixed
*/
public function isCanBuilder()
{
if (false == is_int($this->num) || $this->num <= 0) {
return false;
}
if (false == is_numeric($this->totalMoney) || $this->totalMoney <= 0) {
return false;
}
//均值
$avgMoney = $this->totalMoney / 1.0 / $this->num;
//均值小于最小值
if ($avgMoney < $this->minMoney) {
return false;
}
return true;
}
/**
* 获取剩余金额
* @return mixed
*/
public function getLeftMoney()
{
return $this->leftMoney;
}
/**
* 随机红包生成函数。三角函数。[(1,0.01),($num/2,$avgMoney),($num,0.01)]
*
* @param mixed $x ,1 <= $x <= $this->num;
* @access public
* @return mixed
*/
public function fx($x)
{
if (false == $this->isCanBuilder()) {
return 0;
}
if ($x < 1 || $x > $this->num) {
return 0;
}
$x1 = 1;
$y1 = $this->minMoney;
//我的峰值
$y2 = $this->maxMoney;
//中间点
$x2 = ceil($this->num / 1.0 / 2);
//最后点
$x3 = $this->num;
$y3 = $this->minMoney;
//当x1,x2,x3都是1的时候(竖线)
if ($x1 == $x2 && $x2 == $x3) {
return $y2;
}
// '/_\'三角形状的线性方程
//'/'部分
if ($x1 != $x2 && $x >= $x1 && $x <= $x2) {
$y = 1.0 * ($x - $x1) / ($x2 - $x1) * ($y2 - $y1) + $y1;
return number_format($y, 2, '.', '');
}
//'\'形状
if ($x2 != $x3 && $x >= $x2 && $x <= $x3) {
$y = 1.0 * ($x - $x2) / ($x3 - $x2) * ($y3 - $y2) + $y2;
return number_format($y, 2, '.', '');
}
return 0;
}
/**
* 格式化修红包数据
* @param mixed $leftMoney
* @param array $data
* @return mixed
*/
private function format($leftMoney, array $data)
{
//不能发随机红包
if (false == $this->isCanBuilder()) {
return [$leftMoney, $data];
}
//红包剩余是0
if (0 == $leftMoney) {
return [$leftMoney, $data];
}
//数组为空
if (count($data) < 1) {
return [$leftMoney, $data];
}
//如果是可以有剩余，并且$leftMoney > 0
if ('Can_Left' == $this->formatType
&& $leftMoney > 0) {
return [$leftMoney, $data];
}
//我的峰值
$myMax = $this->maxMoney;
// 如果还有余钱，则尝试加到小红包里，如果加不进去，则尝试下一个。
while ($leftMoney > 0) {
$found = 0;
foreach ($data as $key => $val) {
//减少循环优化
if ($leftMoney <= 0) {
break;
}
//预判
$afterLeftMoney = (double)$leftMoney - 0.01;
$afterVal = (double)$val + 0.01;
if ($afterLeftMoney >= 0 && $afterVal <= $myMax) {
$found = 1;
$data[$key] = number_format($afterVal, 2, '.', '');
$leftMoney = $afterLeftMoney;
//精度
$leftMoney = number_format($leftMoney, 2, '.', '');
}
}
//如果没有可以加的红包，需要结束,否则死循环
if ($found == 0) {
break;
}
}
//如果$leftMoney < 0 ,说明生成的红包超过预算了，需要减少部分红包金额
while ($leftMoney < 0) {
$found = 0;
foreach ($data as $key => $val) {
if ($leftMoney >= 0) {
break;
}
//预判
$afterLeftMoney = (double)$leftMoney + 0.01;
$afterVal = (double)$val - 0.01;
if ($afterLeftMoney <= 0 && $afterVal >= $this->minMoney) {
$found = 1;
$data[$key] = number_format($afterVal, 2, '.', '');
$leftMoney = $afterLeftMoney;
$leftMoney = number_format($leftMoney, 2, '.', '');
}
}
//如果一个减少的红包都没有的话，需要结束，否则死循环
if ($found == 0) {
break;
}
}
return [$leftMoney, $data];
}
}
//维护策略的环境类
class RedPackageBuilder
{
// 实例
protected static $_instance = null;
/**
* Singleton instance（获取自己的实例）
*
* @return $this
*/
public static function getInstance()
{
if (null === self::$_instance) {
self::$_instance = new self();
}
return self::$_instance;
}
/**
* 获取策略【使用反射】
* @param string $type 类型
* @return mixed
* @throws
*/
public function getBuilderStrategy($type)
{
$class = $type . 'PackageStrategy';
if (class_exists($class)) {
return new $class();
} else {
throw new Exception("{$class} 类不存在！");
}
}
public function getRedPackageByDTO(OptionDTO $optionDTO)
{
//获取策略
$builderStrategy = $this->getBuilderStrategy($optionDTO->builderStrategy);
//设置参数
$builderStrategy->setOption($optionDTO);
return $builderStrategy->create();
}
}
class Client
{
public static function main($argv)
{
//固定红包
// $totalMoney,$num,$rangeStart,$rangEnd,$builderStrategy,$randFormatType = 'No_Left'
// $dto = OptionDTO::create(1000,10,100,100,'Equal');
// $data = RedPackageBuilder::getInstance()->getRedPackageByDTO($dto);
// print_r($data);
//随机红包[修数据]
// $dto = OptionDTO::create(400,150,2,4,'RandTriangle');
$dto = OptionDTO::create(240, 150, 1.1, 2.1, 'RandTriangle');
$data = RedPackageBuilder::getInstance()->getRedPackageByDTO($dto);
// print_r($data);
// sort($data);
// print_r($data);
foreach ($data as $key => &$value) {
$value *= 100;
echo $value . "\n";
}
echo array_sum($data);
//随机红包[不修数据]
$dto = OptionDTO::create(5, 10, 0.01, 0.99, 'RandTriangle', 'Can_Left');
$data = RedPackageBuilder::getInstance()->getRedPackageByDTO($dto);
// print_r($data);
}
}
Client::main($argv);
随机红包+固定红包算法[策略模式]
· 8 min read