PHP randomly assigns a specified number to an array of specified books

<?php
$num = 5;
$total = 20;
function randArray($num,$total){
&#160;&#160; &#160;$array = array();
&#160;&#160; &#160;$array = array_pad($array,$num,0);
&#160;&#160; &#160;for($i=0;;$i++){
&#160;&#160; &#160;&#160;&#160; &#160;for($j=0;$j<$num;$j++){
&#160;&#160; &#160;&#160;&#160; &#160;$rand = rand(0,1);
&#160;&#160; &#160;&#160;&#160; &#160;if( (array_sum($array) + $rand) >= $total ){
            $array[$j] += $total - array_sum($array);
            return $array;
        }else{
            $array[$j] += $rand;
        }
        }
    }
}

$array = randArray($num,$total);
echo '<pre class="brush:php;toolbar:false">';
print_r($array);
echo '<br />';
echo array_sum($array);
echo '<br />';
$key = array_rand($array);
echo $key;
echo '<br />';
echo $array[$key];