43 lines
1.2 KiB
PHP
43 lines
1.2 KiB
PHP
<?php
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namespace App\Utils;
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class Probability
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{
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//chance为抽到概率，数值越小，概率越小
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/*
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$arr = [
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['name'=>'1000元手机','chance'=>'1'],
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['name'=>'100元代金券','chance'=>'10'],
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['name'=>'10元代金券','chance'=>'100'],
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['name'=>'谢谢参与','chance'=>'700'],
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];
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*/
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/**
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* 抽奖概率算法
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* @param array $prizeArr 奖品数组
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* @param string $index 概率键名
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* @return mixed 抽到的奖品
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*/
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public static function lotteryRaffle($prizeArr, $index = 'chance')
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{
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$result = null;
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//数组设为集合
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$prize = collect($prizeArr);
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//概率数组的总概率精度
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$proSum = $prize->sum($index);
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//概率数组循环
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$prize->each(function ($item, $key) use (&$proSum, $index, &$result) {
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$randNum = mt_rand(1, $proSum);
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$current_chance = $item[$index];
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if ($randNum <= $current_chance) {
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$result = $item;
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return false;
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}
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$proSum -= $current_chance;
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});
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return $result;
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}
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}
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