选择有限制的多个随机值

Question

我这里有这个代码：

$ids = implode(',', array_rand(array_column($test, 'id', 'id'), 5));

以上代码的作用如下：

"First extract the id column indexing also by the id, then pick 5 random ones, and finally implode into a comma separated list. Since keys must be unique, this has the added benefit of not returning duplicate ids if there happen to be duplicates in the array" 这是我的

现在，如果我将 $arr 从我的旧问题更改为：

Array
(
    [id] => 13
    [pets] => 8
    [num_of_times] => 3
)
Array
(
    [id] => 15
    [pets] => 8
    [num_of_times] => 6
)
Array
(
    [id] => 16
    [pets] => 10
    [num_of_times] => 2
)
Array
(
    [id] => 17
    [pets] => 9
    [num_of_times] => 4
)
Array
(
    [id] => 18
    [pets] => 10
    [num_of_times] => 3
)
Array
(
    [id] => 19
    [pets] => 10
    [num_of_times] => 10
)
Array
(
    [id] => 20
    [pets] => 0
    [num_of_times] => 11
)
Array
(
    [id] => 21
    [pets] => 8
    [num_of_times] => 9
)
Array
(
    [id] => 22
    [pets] => 9
    [num_of_times] => 0
)
Array
(
    [id] => 23
    [pets] => 4
    [num_of_times] => 3
)
Array
(
    [id] => 24
    [pets] => 0
    [num_of_times] => 1
)
Array
(
    [id] => 40
    [pets] => 8
    [num_of_times] => 0
)
Array
(
    [id] => 43
    [pets] => 2
    [num_of_times] => 2
)

num_of_times是可以选择id或"user"的次数。

所以如果我有这样的 for loop：

for ($i = 1; $i <= 10; $i++) {
    $ids = implode(',', array_rand(array_column($arr, 'id', 'id'), 5));
    echo $ids;
}

我怎样才能确保，例如，id 为 13 的第一个数组 NOT 进入 $ids more超过 3 次，但可以进入 $ids 3 次或更少，当处于 for loop 时？（这适用于所有 ID）

例如，最终结果是这样的：

13,15,17,19,23
13,21,22,40,43
13,15,17,19,23
15,23,24,40,43 // 13 cannot be selected anymore because it already hit the "num_of_times" limit which is 3 for the number 13. Same thing for all the other numbers/id's
...
...
...
...
...
...

Answer 1

这是解决这个问题的一种方法

$num = array_column($test, 'num_of_times', 'id'); // get each num_of_times with id as index
for ($ids = '', $i = 1; $i <= 10; $i++) {         // Your for loop
    $num = array_filter($num);                    // Filter $num array
    $rand = array_rand($num, 5);                  // get 5 random element
    $ids .= implode(',', $rand) . '<br>';         // implode then concatenate to $ids var
    foreach ($rand as $id) {                      // Run a foreach loop to $rand array
        $num[$id]--;                              // Decrement num_of_times
    }
}
echo $ids;  // Echo result

Answer 2

嗨，兄弟，试试我的代码，看看它是否符合你的需要。如果你想限制每个数据的使用，你只需要添加更多的数组数据。

<?php

$arr = Array(Array
(
   'id' => 13,
   'pets' => 8,
   'num_of_times' => 3
),Array(
   'id' => 15,
  'pets' => 8,
  'num_of_times' => 6
),Array (
'id' => 16,
'pets' => 10,
'num_of_times' => 2
),Array(
'id' => 17,
'pets' => 9,
'num_of_times' => 4
),Array(
'id' => 18,
'pets' => 10,
'num_of_times' => 3
),Array(
'id' => 19,
'pets' => 10,
'num_of_times' => 10
),Array(
'id' => 20,
'pets' => 0,
'num_of_times' => 11
),Array(
'id' => 21,
'pets' => 8,
'num_of_times' => 9
),Array(
'id' => 22,
'pets' => 9,
'num_of_times' => 0
),Array(
'id' => 23,
'pets' => 4,
'num_of_times' => 3
),Array(
'id' => 24,
'pets' => 0,
'num_of_times' => 1
),Array(
'id' => 40,
'pets' => 8,
'num_of_times' => 0
),Array(
'id' => 43,
'pets' => 2,
'num_of_times' => 2,
));


$checker = array(); //array that holds the id with the count of use
$remove =array(); // array to remove in array to random 

for ($i = 1; $i <= 10; $i++) {

$newArray =array_diff(array_column($arr, 'id', 'id'),$remove); //the newarray to use in random with remove function for the id that has been used for 3x

$ids = array_rand($newArray, 5); 

foreach($ids as $id){

    if(!array_key_exists($id,$checker)){ // check if the id is existing in the checker key if yes

        $checker[$id] = 1; // insert value 1 in the array as the count of use

    }else{

        if(!empty($checker[$id]) && $checker[$id] < 3){ //check if the array has a value lower than 3

            $checker[$id]=$checker[$id]+1; // then add 1 value for the data as a increment of data usage

            if($checker[$id] == 3){ //check if da is already used 3x
                $remove[]=$id; //then add it to the variable remove
            }
        }
    }




}
echo implode(',',$ids).'</br>';

}

echo '<pre>';
echo print_r($checker);
echo '</pre>';

选择有限制的多个随机值

Selecting multiple & random values with limit

php

arrays

for-loop

random

implode