PHP wechat red packet grabbing algorithm

php Wechat red packet algorithm

function qiangHongbao() {
    $total=10;// Total 
	$num=8;//  Divide into 8 Red envelopes , Support 8 People receive at random  
	$min=0.01;// Everyone can at least receive 0.01 element  
	for ($i=1;$i<$num;$i++) { 
	    $safe_total=($total-($num-$i)*$min)/($num-$i);// Random safety upper limit  
	    $money=mt_rand($min*100,$safe_total*100)/100; 
	    $total=$total-$money; 
	    echo ' The first '.$i.' Red envelopes ：'.$money.'  element , balance ：'.$total.'  element  <br/>'; 
	} 
	echo ' The first '.$num.' Red envelopes ：'.$total.'  element , balance ：0  element '; 
}

//  Output results 
//  The first 1 Red envelopes ：0.08  element , balance ：9.92  element 
//  The first 2 Red envelopes ：0.82  element , balance ：9.1  element 
//  The first 3 Red envelopes ：1.4  element , balance ：7.7  element 
//  The first 4 Red envelopes ：0.87  element , balance ：6.83  element 
//  The first 5 Red envelopes ：1.07  element , balance ：5.76  element 
//  The first 6 Red envelopes ：2.47  element , balance ：3.29  element 
//  The first 7 Red envelopes ：1.01  element , balance ：2.28  element 
//  The first 8 Red envelopes ：2.28  element , balance ：0  element