php-在与模式x相关的间隔内生成随机数

<?php 

function generateRandomWithMode($min,$max,$mode,$size){
    if(!($mode >= $min && $mode <= $max)){
        throw new Exception("Mode $mode is not between $min and $max range");       
    }

    $half_count = intval($size / 2);

    /* 
        set mode frequency as half of the size + any random value generated between 0 and half_count. This ensures
        that the mode you provided as the function parameter always remains the mode of the set of random values.
    */
    $mode_frequency = $half_count + rand(0,$half_count);

    $random_values = [];
    $size -= $mode_frequency;

    while($mode_frequency-- > 0) $random_values[] = $mode;
    while($size-- > 0) $random_values[] = rand($min,$max);

    shuffle($random_values);
    return $random_values;
}

print_r(generateRandomWithMode(1,100,4,10));

Array
(
    [0] => 4
    [1] => 63
    [2] => 4
    [3] => 4
    [4] => 24
    [5] => 4
    [6] => 4
    [7] => 4
    [8] => 12
    [9] => 4
)