- <?php
- /**
- * 抽奖函数升级版,可排除若干奖项
- */
- class Lottery {
- static public $rate;
- static public $ignore;
- /**
- *
- * @param type $rate 概率设置
- * @param type $ignore 忽略的奖项
- * @return 调用实例化后的对象方法
- * @example Lottery::runOnce(array(20, 10, 10, 10), array(0));
- */
- static public function runOnce($rate = array(10, 10, 10, 10), $ignore = array()) {
- self::$rate = $rate;
- self::$ignore = $ignore;
- $obj = new self;
- return $obj->lotteryProcess();
- }
- /**
- * 处理抽奖
- * @return type
- */
- public function lotteryProcess() {
- $rateSum = array_sum(self::$rate); //概率之和
- //考虑用户输入的概率之和不等于100
- if ($rateSum < 100) {
- array_push(self::$rate, 100 - $rateSum);
- } elseif ($rateSum > 100) {
- die('The rate sum over 100%!');
- }
- //处理忽略奖项
- $rateCount = count(self::$rate);
- foreach (self::$rate as $key => $value) {
- if (in_array($key, self::$ignore)) {
- self::$rate[$rateCount - 1]+=self::$rate[$key];
- self::$rate[$key] = 0;
- }
- $seedRaw[$key] = self::$rate[$key] * 100; //概率放大100被备用
- }
- $seed = $this->arraySum($seedRaw); //处理数组
- $randVal = mt_rand(0, 10000);
- return $this->judge($seed, $randVal);
- }
- /**
- * 从0-10000重新组织数组,每个值为之前各项的累加
- * @param array $seedRaw
- * @return array
- */
- private function arraySum(array$seedRaw) {
- foreach ($seedRaw as $key => $value) {
- $tmpSum = 0;
- for ($i = 0; $i < $key; $i++) {
- $tmpSum+=$seedRaw[$i];
- }
- $seed[$key] = $tmpSum;
- }
- array_push($seed, 10000);
- return $seed;
- }
- /**
- * 根据随机值判断此次中了第几个奖项
- * @param type $seed
- * @param type $rand
- * @return int
- */
- private function judge($seed, $rand) {
- array_push($seed, NULL); //凑数
- for ($i = 0; $i < count($seed) - 1; $i++) {
- if ($rand >= $seed[$i] && $rand < $seed[$i + 1]) {
- return $i;
- }
- }
- }
- }
- ini_set('display_errors', 'on');
- $l0 = 0;
- $l1 = 0;
- $l2 = 0;
- $l3 = 0;
- $l4 = 0;
- $l5 = 0;
- for ($i = 0; $i <= 10000; $i++) {
- $result = Lottery::runOnce(array(20, 10, 10, 10), array(0, 1));
- if ($result === 0)
- $l0++;
- if ($result == 1)
- $l1++;
- if ($result == 2)
- $l2++;
- if ($result == 3)
- $l3++;
- if ($result == 4)
- $l4++;
- }
- echo '0:' . $l0 . '<br/>1:' . $l1 . '<br/>2:' . $l2 . '<br/>3:' . $l3 . '<br/>4:' . $l4;
- //该片段来自于http://www.codesnippet.cn/detail/070120148438.html
来源: http://www.codesnippet.cn/detail/070120148438.html