简单模仿微信发送随机红包写的算法
/** * 随机红包算法 * $mony分钱随机发给$count个人，$height越大，随机金额大小分化越大 */ function rand_redpack($mony,$count = 30, $height = 4){ if($mony < $count) return false; //不够分 if($height <= 0) return false; //$height只能大于或等于0 $arr = []; for ($x=0; $x<$count; $x++) $arr[] = 1; $restMony = $mony - $count; $roll = function($arr, $restMony) use (&$roll, $height) { //匿名递归写法 if($restMony === 0) return $arr; $index = rand(0,count($arr)-1); $passe = ceil($height*round($restMony/count($arr))); $spend = $restMony>=$passe ? rand(1, $passe) : rand(1, $restMony); $arr[$index] += $spend; return $roll($arr, $restMony-$spend); }; return $roll($arr, $restMony); }; //假如我们把50元红包发给30个人 rand_redpack(5000, 30, 4); 结果 array:30 [ 0 => 99 1 => 176 2 => 14 3 => 160 4 => 231 5 => 65 6 => 178 7 => 36 8 => 1 9 => 95 10 => 43 11 => 23 12 => 92 13 => 220 14 => 16 15 => 638 16 => 49 17 => 1 18 => 528 19 => 19 20 => 2 21 => 505 22 => 620 23 => 41 24 => 9 25 => 451 26 => 181 27 => 55 28 => 104 29 => 348 ] rand_redpack(5000, 30, 0.1); array:30 [ 0 => 194 1 => 154 2 => 134 3 => 130 4 => 177 5 => 178 6 => 178 7 => 122 8 => 174 9 => 201 10 => 154 11 => 176 12 => 164 13 => 211 14 => 146 15 => 157 16 => 233 17 => 198 18 => 121 19 => 189 20 => 108 21 => 99 22 => 155 23 => 165 24 => 163 25 => 185 26 => 171 27 => 162 28 => 230 29 => 171 ]