<?php
/**
* Created by PhpStorm.
* User: kevin_yang
* Date: 2018/1/4
* Time: 22:49
*/
header(‘content-type:text/html;charset=utf-8‘);
ini_set(‘memory_limit‘, ‘256M‘);
require_once(‘CreateReward.php‘);
require_once(‘Reward.php‘);
$total = 100;
$num = 10;
$max = mt_rand(1,2)*(ceil($total/$num));
$min = 0.1;
$create_reward = new CreateReward();
//性能测试
for($i=0; $i<5; $i++) {
$time_start = microtime_float();
$reward_arr = $create_reward->random_red($total, $num, $max, $min);
$time_end = microtime_float();
$time[] = $time_end - $time_start;
}
//echo array_sum($time)/5;
function microtime_float()
{
list($usec, $sec) = explode(" ", microtime());
return ((float)$usec + (float)$sec);
}
//检查结果
$reward_arr = $create_reward->random_red($total, $num, $max, $min);
sort($reward_arr);//正序，最小的在前面
$sum = 0;
$min_count = 0;
$max_count = 0;
foreach($reward_arr as $i => $val) {
if ($i<3) {
echo "<br />第".($i+1)."个红包，金额为：".$val."<br />";
}
if ($val == $max) {
$max_count++;
}
if ($val < $min) {
$min_count++;
}
$val = $val*100;
$sum += $val;
}
echo "<pre />";var_dump($reward_arr);
//检测钱是否全部发完
echo ‘<hr>已生成红包总金额为：‘.($sum/100).‘;总个数为：‘.count($reward_arr).‘<hr>‘;
//检测有没有小于0的值
echo "<br />最大值:".($val/100).‘,共有‘.$max_count.‘个最大值，共有‘.$min_count.‘个值比最小值小‘;
//正态分布图
//对红包进行排序一下以显示正态分布特性
$reward_arr = $create_reward->random_red($total, $num, $max, $min);
$show = array();
rsort($reward_arr);
foreach($reward_arr as $k=>$value)
{
$t=$k%2;
if(!$t) $show[]=$value;
else array_unshift($show,$value);
}
//echo "<pre>";var_dump($show);die;
echo "设定最大值为:".$max.‘,最小值为:‘.$min.‘<hr />‘;
echo "<table style=‘font-size:12px;width:600px;border:1px solid #ccc;text-align:left;‘><tr><td>红包金额</td><td>图示</td></tr>";
foreach($show as $val)
{
#线条长度计算
$width=intval($num*$val*300/$total);
echo "<tr><td> {$val} </td><td width=‘500px;text-align:left;‘><hr style=‘width:{$width}px;height:3px;border:none;border-top:3px double red;margin:0 auto 0 0px;‘></td></tr>";
}
echo "</table>";
引入文件Reward.php
<?php
/*
* Author:xx_lufei
* Time:2016年9月14日09:55:36
* Note:红包生成随机算法
*/
class Reward
{
public $rewardMoney; #红包金额、单位元
public $rewardNum; #红包数量
#执行红包生成算法
public function splitReward($rewardMoney, $rewardNum, $max, $min)
{
#传入红包金额和数量，因为小数在计算过程中会出现很大误差，所以我们直接把金额放大100倍，后面的计算全部用整数进行
$min = $min * 100;
$max = $max * 100;
#预留出一部分钱作为误差补偿，保证每个红包至少有一个最小值
$this->rewardMoney = $rewardMoney * 100 - $rewardNum * $min;
$this->rewardNum = $rewardNum;
#计算出发出红包的平均概率值、精确到小数4位。
$avgRand = 1 / $this->rewardNum;
$randArr = array();
#定义生成的数据总合sum
$sum = 0;
$t_count = 0;
while ($t_count < $rewardNum) {
#随机产出四个区间的额度
$c = rand(1, 100);
if ($c < 15) {
$t = round(sqrt(mt_rand(1, 1500)));
} else if ($c < 65) {
$t = round(sqrt(mt_rand(1500, 6500)));
} else if ($c < 95) {
$t = round(sqrt(mt_rand(6500, 9500)));
} else {
$t = round(sqrt(mt_rand(9500, 10000)));
}
++$t_count;
$sum += $t;
$randArr[] = $t;
}
#计算当前生成的随机数的平均值，保留4位小数
$randAll = round($sum / $rewardNum, 4);
#为将生成的随机数的平均值变成我们要的1/N，计算一下每个随机数要除以的总基数mixrand。此处可以约等处理，产生的误差后边会找齐
#总基数 = 均值/平均概率
$mixrand = round($randAll / $avgRand, 4);
#对每一个随机数进行处理，并乘以总金额数来得出这个红包的金额。
$rewardArr = array();
foreach ($randArr as $key => $randVal) {
#单个红包所占比例randVal
$randVal = round($randVal / $mixrand, 4);
#算出单个红包金额
$single = floor($this->rewardMoney * $randVal);
#小于最小值直接给最小值
if ($single < $min) {
$single += $min;
}
#大于最大值直接给最大值
if ($single > $max) {
$single = $max;
}
#将红包放入结果数组
$rewardArr[] = $single;
}
#对比红包总数的差异、将差值放在第一个红包上
$rewardAll = array_sum($rewardArr);
$rewardArr[0] = $rewardMoney * 100 - ($rewardAll - $rewardArr[0]);#此处应使用真正的总金额rewardMoney，$rewardArr[0]可能小于0
#第一个红包小于0时,做修正
if ($rewardArr[0] < 0) {
rsort($rewardArr);
$this->add($rewardArr, $min);
}
rsort($rewardArr);
#随机生成的最大值大于指定最大值
if ($rewardArr[0] > $max) {
#差额
$diff = 0;
foreach ($rewardArr as $k => &$v) {
if ($v > $max) {
$diff += $v - $max;
$v = $max;
} else {
break;
}
}
$transfer = round($diff / ($this->rewardNum - $k + 1));
$this->diff($diff, $rewardArr, $max, $min, $transfer, $k);
}
return $rewardArr;
}
#处理所有超过最大值的红包
public function diff($diff, &$rewardArr, $max, $min, $transfer, $k)
{
#将多余的钱均摊给小于最大值的红包
for ($i = $k; $i < $this->rewardNum; $i++) {
#造随机值
if ($transfer > $min * 20) {
$aa = rand($min, $min * 20);
if ($i % 2) {
$transfer += $aa;
} else {
$transfer -= $aa;
}
}
if ($rewardArr[$i] + $transfer > $max) continue;
if ($diff - $transfer < 0) {
$rewardArr[$i] += $diff;
$diff = 0;
break;
}
$rewardArr[$i] += $transfer;
$diff -= $transfer;
}
if ($diff > 0) {
$i++;
$this->diff($diff, $rewardArr, $max, $min, $transfer, $k);
}
}
#第一个红包小于0,从大红包上往下减
public function add(&$rewardArr, $min)
{
foreach ($rewardArr as &$re) {
$dev = floor($re / $min);
if ($dev > 2) {
$transfer = $min * floor($dev / 2);
$re -= $transfer;
$rewardArr[$this->rewardNum - 1] += $transfer;
} elseif ($dev == 2) {
$re -= $min;
$rewardArr[$this->rewardNum - 1] += $min;
} else {
break;
}
}
if ($rewardArr[$this->rewardNum - 1] > $min || $rewardArr[$this->rewardNum - 1] == $min) {
return;
} else {
$this->add($rewardArr, $min);
}
}
}
引入文件CreateReward.php
<?php
class CreateReward{
/*
* 生成红包
* author xx 2018年9月23日13:53:38
* @param int $total 红包总金额
* @param int $num 红包总数量
* @param int $max 红包最大值
*
*/
public function random_red($total, $num, $max, $min)
{
#总共要发的红包金额，留出一个最大值;
$total = $total - $max;
$reward = new Reward();
$result_merge = $reward->splitReward($total, $num, $max - 0.01, $min);
sort($result_merge);
$result_merge[1] = $result_merge[1] + $result_merge[0];
$result_merge[0] = $max * 100;
foreach ($result_merge as &$v) {
$v = floor($v) / 100;
}
return $result_merge;
}
}
运行结果
第1个红包，金额为：6.67
第2个红包，金额为：7.73
第3个红包，金额为：7.83
array(10) {
[0]=>
float(6.67)
[1]=>
float(7.73)
[2]=>
float(7.83)
[3]=>
float(8.46)
[4]=>
float(8.89)
[5]=>
float(9.21)
[6]=>
float(10.15)
[7]=>
float(10.48)
[8]=>
float(10.58)
[9]=>
float(20)
}
已生成红包总金额为：100;总个数为：10
原文地址：https://www.cnblogs.com/kevin-yang123/p/10044742.html
时间： 2024-08-23 23:28:45