php 实现抽奖功能

亦凉 2023-10-06 16:16 16阅读 0赞

#### 阅读目录 ####

*  抽奖功能 1
 *  抽奖功能 2

## 抽奖功能 1 ##

最近做的小程序有一个抽奖功能，这里记录下实现抽奖功能的具体流程

前提：

有一组奖品数据如下

<table> 
 <tbody> 
  <tr> 
   <td colspan="1">id</td> 
   <td>奖品(prize)</td> 
   <td>概率(rate)</td> 
   <td>数量(num)</td> 
   <td>已抽数量(prize_num)</td> 
  </tr> 
  <tr> 
   <td colspan="1">1</td> 
   <td>一等奖</td> 
   <td>10%</td> 
   <td>10</td> 
   <td>0</td> 
  </tr> 
  <tr> 
   <td colspan="1">2</td> 
   <td>二等奖</td> 
   <td>15%</td> 
   <td>20</td> 
   <td>0</td> 
  </tr> 
  <tr> 
   <td colspan="1">3</td> 
   <td>三等奖</td> 
   <td>35%</td> 
   <td>50</td> 
   <td>0</td> 
  </tr> 
 </tbody> 
</table>

根据如上实现抽奖如下($prizes表示上面表格数据)

public function promise()
    	{
        
    		$prizes = [
    			[
    				'id' => 1,
    				'prize' => '一等奖',
    				'rate' => '0.1',
    				'num' => '10',
    				'prize_num' => '0',
    			],
    			[
    				'id' => 2,
    				'prize' => '二等奖',
    				'rate' => '0.15',
    				'num' => '20',
    				'prize_num' => '0',
    			],
    			[
    				'id' => 3,
    				'prize' => '三等奖',
    				'rate' => '0.3',
    				'num' => '50',
    				'prize_num' => '0',
    			],
    		];
    		//进行抽奖
    		$data = [];
    		foreach ($prizes as $prize) {
        
    		    if (($prize['num'] - $prize['prize_num']) > 0) {
        
    		        $data[$prize['id']] = 100 * ($prize['rate']);
    		    }
    		};
    		//获取所有奖品的总概率
    		$sum = array_sum($data);
    		$countSum = 100;
    		if ($sum < $countSum) {
        
    		    $data[0] = $countSum - $sum;//不满100%，表示没有抽取到奖品
    		}
    		$result = 0;
    		//概率数组总精度
    		//概率数组循环
    		foreach ($data as $key => $value) {
        
    		    $randNum = mt_rand(1, $countSum);
    		    if ($randNum <= $value) {
        
    		        $result = $key;
    		        break;
    		    } else {
        
    		        $countSum -= $value;
    		    }
    		}
    		unset($arr);
    		echo $result;//抽到的ID值,0表示没有抽到奖品
    
    	}

根据如上就可以实现抽奖功能

![在这里插入图片描述][20210201192221260.png]

## 抽奖功能 2 ##

<?php
    
    function gl()
    {
        
        $prize_arr = [
            '0' => ['id' => 1, 'prize' => '奖品1', 'v' => 20],
            '1' => ['id' => 2, 'prize' => '奖品2', 'v' => 10],
            '2' => ['id' => 3, 'prize' => '奖品3', 'v' => 20],
            '3' => ['id' => 4, 'prize' => '奖品4', 'v' => 5],
            '4' => ['id' => 5, 'prize' => '奖品5', 'v' => 19],
            '5' => ['id' => 6, 'prize' => '奖品6', 'v' => 5],
            '6' => ['id' => 7, 'prize' => '奖品7', 'v' => 10],
            '7' => ['id' => 8, 'prize' => '奖品8', 'v' => 10],
        ];
    
        foreach ($prize_arr as $key => $val)
        {
        
            $arr[$val['id']] = $val['v'];
        }
    
        $rid = get_prize($arr); //根据概率获取奖项id
        $data = $prize_arr[$rid - 1];
        return $data;
    }
    
    function get_prize($proArr) 
    {
        
        $result = '';
    
        //概率数组的总概率精度
        $proSum = array_sum($proArr);
    
        //概率数组循环
        foreach ($proArr as $key => $proCur)
        {
        
            $randNum = mt_rand(1, $proSum);
            if ($randNum <= $proCur)
            {
        
                $result = $key;
                break;
            } else {
        
                $proSum -= $proCur;
            }
        }
        unset ($proArr);
        return $result;
    }
    
    print_r(gl());

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAd2djaGVufg_size_13_color_FFFFFF_t_70_g_se_x_16]

[20210201192221260.png]: https://img-blog.csdnimg.cn/20210201192221260.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAd2djaGVufg_size_13_color_FFFFFF_t_70_g_se_x_16]: https://img-blog.csdnimg.cn/42c569cd249b439e974a3e22bb1b41ba.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBAd2djaGVufg==,size_13,color_FFFFFF,t_70,g_se,x_16