<?php
/**
* User: phpmianshi.com
* Date: 2020/3/31
* Time: 10:16
*/
class redPack
{
/**
* 測試紅包生成
*/
public function test(){
for($i=0;$i<5;$i++){
$num[$i]['a']=$this->getBonus(5,4);
}
var_dump($num);
}
/**
*生成紅包數組
* @param $bonus_total 紅包總額
* @param $bonus_count 紅包個數
* @param $bonus_max 每個小紅包的最大額
* @param $bonus_min 每個小紅包的最小額
* @return 存放生成的每個小紅包的值的一維數組
*/
function getBonus($total = 0, $count = 0)
{
$yushu = ($total - intval($total)); //如果金額爲小數則取出小數位
$bonus_total = ($total - $yushu) * 100; //如果金額爲小數則去除小數小計算分配
$bonus_count = $count;
$result = array();
if ($bonus_total / $bonus_count > 1) {
if (($bonus_total - $bonus_total / 4) / ($bonus_count - 1) >= 1) {
$bonus_max = $bonus_total / 4;
if (($bonus_total / 4) == ($bonus_total / $bonus_count)) {
$bonus_max += 50;
}
} else {
for ($j = 0; $j < $count; $j++) {
$result[$j] = ($bonus_total / $bonus_count) / 100;
}
$r = rand(0, $count - 1);
$result[$r] = ($bonus_total - $bonus_count * 1 + 1) / 100;
//如果還有負數產生就重新分配
$attr = array();
foreach ($result as $k => $v) {
$attr[$k]['money'] = $v;
$attr[$k]['yili'] = 0;
}
return $attr;
}
} else {
for ($k = 0; $k < $count; $k++) {
$result[$k] = $total / $count / 100;
}
//如果還有負數產生就重新分配
$attr = array();
foreach ($result as $k => $v) {
$attr[$k]['money'] = $v;
$attr[$k]['yili'] = 0;
}
return $attr;
}
$bonus_min = 1;
$average = $bonus_total / $bonus_count;
//$average = $bonus_total/ $bonus_count;
$a = $average - $bonus_min;
$b = $bonus_max - $bonus_min;
//這樣的隨機數的概率實際改變了,產生大數的可能性要比產生小數的概率要小。
//這樣就實現了大部分紅包的值在平均數附近。大紅包和小紅包比較少。
$range1 = $this->sqr($average - $bonus_min);
$range2 = $this->sqr($bonus_max - $average);
for ($i = 0; $i < $bonus_count; $i++) {
//因爲小紅包的數量通常是要比大紅包的數量要多的,因爲這裏的概率要調換過來。
//當隨機數>平均值,則產生小紅包
//當隨機數<平均值,則產生大紅包
if (rand($bonus_min, $bonus_max) > $average) {
// 在平均線上減錢
$temp = $bonus_min + $this->xRandom($bonus_min, $average);
$result[$i] = $temp;
$bonus_total -= $temp;
} else {
// 在平均線上加錢
$temp = $bonus_max - $this->xRandom($average, $bonus_max);
$result[$i] = $temp;
$bonus_total -= $temp;
}
}
// 如果還有餘錢,則嘗試加到小紅包裏,如果加不進去,則嘗試下一個。
while ($bonus_total > 0) {
for ($i = 0; $i < $bonus_count; $i++) {
if ($bonus_total > 0 && $result[$i] < $bonus_max) {
$result[$i]++;
$bonus_total--;
}
}
}
// 如果錢是負數了,還得從已生成的小紅包中抽取回來
while ($bonus_total < 0) {
for ($i = 0; $i < $bonus_count; $i++) {
if ($bonus_total < 0 && $result[$i] > $bonus_min) {
$result[$i]--;
$bonus_total++;
}
}
}
//如果還有負數產生就重新分配
$attr = array();
//隨機一個小紅包加入金額小數位
$rands = rand(0, ($bonus_count - 1));
$result[$rands] += $yushu * 100;
$nums = 0;
//處理輸出
foreach ($result as $k => $v) {
if ($v < 1) {
$this->getBonus();
die;
}
$attr[$k]['money'] = $v / 100;
$attr[$k]['yili'] = 0;
$nums += $v;
}
//dump($nums);
//dump($result);
return $attr;
}
/**
* 求一個數的平方
* @param $n
*/
function sqr($n)
{
return $n * $n;
}
/**
* 生成min和max之間的隨機數,但是概率不是平均的,從min到max方向概率逐漸加大。
* 先平方,然後產生一個平方值範圍內的隨機數,再開方,這樣就產生了一種“膨脹”再“收縮”的效果。
*/
function xRandom($bonus_min, $bonus_max)
{
$sqr = intval($this->sqr($bonus_max - $bonus_min));
$rand_num = rand(0, ($sqr - 1));
return intval(sqrt($rand_num));
}
}
//測試生成紅包的數組
$redPack=new redPack();
$redPack->test();