php大转盘抽奖

对于php抽奖概率在之前章节有

http://www.cnblogs.com/shiwenhu/p/5650269.html

现在来设计对于大转盘的中奖，这里定义的数组比之前多了个中间的显示中奖的度数

<?php

$prize_arr = array( 
    '0' => array('id' => 1, 'min' => 1, 'max' => 29, 'prize' => '一等奖', 'v' => 1), 
    '1' => array('id' => 2, 'min' => 302, 'max' => 328, 'prize' => '二等奖', 'v' => 2), 
    '2' => array('id' => 3, 'min' => 242, 'max' => 268, 'prize' => '三等奖', 'v' => 5), 
    '3' => array('id' => 4, 'min' => 182, 'max' => 208, 'prize' => '四等奖', 'v' => 7), 
    '4' => array('id' => 5, 'min' => 122, 'max' => 148, 'prize' => '五等奖', 'v' => 10), 
    '5' => array('id' => 6, 'min' => 62, 'max' => 88, 'prize' => '六等奖', 'v' => 25), 
    '6' => array('id' => 7, 'min' => array(32, 92, 152, 212, 272, 332), 
        'max' => array(58, 118, 178, 238, 298, 358), 'prize' => '七等奖', 'v' => 50) 
    //min数组表示每个个奖项对应的最小角度 max表示最大角度 
    //prize表示奖项内容，v表示中奖几率(若数组中七个奖项的v的总和为100，如果v的值为1，则代表中奖几率为1%，依此类推) 
 );

function getRand($proArr) { 


    $data = ''; 


    $proSum = array_sum($proArr); //概率数组的总概率精度  





    foreach ($proArr as $k => $v) { //概率数组循环 


        $randNum = mt_rand(1, $proSum); 


        if ($randNum <= $v) { 


            $data = $k; 


            break; 


        } else { 


            $proSum -= $v; 


        } 


    } 


    unset($proArr); 





    return $data; 


}

foreach ($prize_arr as $v) { 


    $arr[$v['id']] = $v['v']; 


} 





$prize_id = getRand($arr); //根据概率获取奖项id  





$res = $prize_arr[$prize_id - 1]; //中奖项  


$min = $res['min']; 


$max = $res['max']; 


if ($res['id'] == 7) { //七等奖  


    $i = mt_rand(0, 5); 


    $data['angle'] = mt_rand($min[$i], $max[$i]); 


} else { 


    $data['angle'] = mt_rand($min, $max); //随机生成一个角度  


} 


$data['prize'] = $res['prize']; 





echo json_encode($data);

?>