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PHP implements WeChat lucky red envelope

WBOY
WBOYOriginal
2016-07-29 09:08:311150browse
<?php
$result = sendHB(100, 10);
var_export($result);
echo array_sum($result);

/**
 * 拼手气红包实现
 * 生成num个随机数,每个随机数占随机数总和的比例*money_total的值即为每个红包的钱额
 * 考虑到精度问题,最后重置最大的那个红包的钱额为money_total-其他红包的总额
 * 浮点数比较大小,使用number_format,精确到2位小数
 *
 * @param double $money_total  总钱额, 每人最少0.01,精确到2位小数
 * @param int $num 发送给几个人
 * @return array num个元素的一维数组,值是随机钱额
 */
function sendHB($money_total, $num) {
	if($money_total < $num*0.01) {
		exit(&#39;钱太少&#39;);
	}

	$rand_arr = array();
	for($i=0; $i<$num; $i++) {
		$rand = rand(1, 100);
		$rand_arr[] = $rand;
	}

	$rand_sum = array_sum($rand_arr);
	$rand_money_arr = array();
	$rand_money_arr = array_pad($rand_money_arr, $num, 0.01);  //保证每个红包至少0.01

	foreach ($rand_arr as $key => $r) {
		$rand_money = number_format($money_total*$r/$rand_sum, 2);

		if($rand_money <= 0.01 || number_format(array_sum($rand_money_arr), 2) >= number_format($money_total, 2)) {
			$rand_money_arr[$key] = 0.01;
		} else {
			$rand_money_arr[$key] = $rand_money;
		}

	}

	$max_index = $max_rand = 0;
	foreach ($rand_money_arr as $key => $rm) {
		if($rm > $max_rand) {
			$max_rand = $rm;
			$max_index = $key;
		}
	}

	unset($rand_money_arr[$max_index]);
	//这里的array_sum($rand_money_arr)一定是小于$money_total的
	$rand_money_arr[$max_index] = number_format($money_total - array_sum($rand_money_arr), 2);
	
	ksort($rand_money_arr);
	return $rand_money_arr;
}

The above introduces the implementation of WeChat lucky red envelopes in PHP, including the relevant aspects. I hope it will be helpful to friends who are interested in PHP tutorials.

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