Among 36 numbers between 1-36, 5 are randomly selected so that the sum is 100

Originally, a friend asked me to help write a method in excel: randomly select 5 of the 36 numbers between 1-36 so that the sum is 100:

I am not very good at using excel, so I try to write a method in php:

Imagine: If the five numbers all fluctuate around 20, and the fluctuation values ​​cancel each other out, then the random number will be easy to find.

Idea: a_random+b_random+a_offset+c_random+b_offset+d_random+c_offset+e_random

Where a_offset is the fluctuation value of a_random and the middle value 20, then it means a_random+a_offset=20, similarly b_random+b_offset=20, etc.

Then finally (a_random+a_offset)+(b_random+b_offset)+(c_random+c_offset)+d_random+e_random=60+d_random+e_random;

The last number e_random is not random, it is derived from 100-60-d_random. Then you only need to randomly find d_random and then judge whether it meets the requirements.
If you have a better method, you can tell me in the thread, thank you!

//Parameter settings
$total=100;
$min_num=1;
$max_num=36;
$times=5;

$average=$total/$times;
$ now=0;
for($i=0;$i<$times;$i++)
{
 $off=0;
 $tmp=0;
 if($i==$times-1)
 {
 $tmp=$total-$now;
 if($tmp>$max_num||$tmp<0)
 {
 $off=$now=0;
 $i=0;
 // echo "$tmp|" ;//Data that does not meet the requirements
 unset($num);
 $tmp=rand($min_num,$max_num);
 $off=$tmp-$average;
 $now=$now+$tmp;
 $num []=$tmp;
 continue;
 }
 else
 {
 $num[]=$tmp;
 break;
 }
 }

 if($off==0)
 {
 $tmp=rand($ min_num,$max_num);
 }
 else
 {
 $tmp=rand($min_num-$off,$max_num-$off);
 $tmp=($tmp+$off);
 }
 $off=$tmp -$average;
 $now=$now+$tmp;
 $num[]=$tmp;
}

// Test
$con='';
foreach($num as $val)
{
 $total_my =$total_my+$val;
 echo $con."$val";
 $con="+";
}
echo '='.$total_my;
exit;
?>