CODEWITHSUNDEEP
php
n0tez4nene
n0tez4nene

Reputation: 1

random numbers for array keys, and the same random number for duplicates

I'm trying to split tasks for two persons randomly by generating random number for every task from 1 to 2.

the problem is that I have duplicate tasks. how to generate the same number for duplicates without having to delete them ? example :

<?php 
$tasks = array('task1','task4','task2','task3','task4','task3','task4','task5'); 


foreach($tasks as $task)
{
    $rand = rand(1,2);
    $array = array('task' => $task,'rand'=> $rand);
    echo $array['task']."==>";
    echo $array['rand']."<br>";
}

?>

Upvotes: 0

Views: 89

Answers (2)

Michel
Michel

Reputation: 4157

You could us array_fill_keys() to create an array with all the tasks as keys, then use array_walk() to assign random numbers to all the keys.

$tasks = array('task1','task4','task2','task3','task4','task3','task4','task5'); 

//use the tasks as keys for a new array. Duplicates will be filtered out.
$task_rand = array_fill_keys( $tasks, false );

//then "walk" the new array, assigning a randum number to each task
array_walk($task_rand, function(&$value){$value= rand(1,2);});

//sort the array, so task1 comes before task2 etc
ksort($task_rand);

The result of `$task_rand`:
Array
(
[task1] => 2
[task2] => 1
[task3] => 2
[task4] => 1
[task5] => 1
)

Upvotes: 0

akrys
akrys

Reputation: 563

The easy way: Use array keys

$tasks = array('task1', 'task4', 'task2', 'task3', 'task4', 'task3', 'task4', 'task5');

$output = [];

foreach ($tasks as $task) {
    if (!isset($output[$task])) {
        $output[$task] = rand(1, 2);
    }
}

Result: var_dump($output);

array (size=5)
  'task1' => int 2
  'task4' => int 2
  'task2' => int 2
  'task3' => int 1
  'task5' => int 1

Get the number for a certain task: var_dump($output['task3']);

int 1

This is easy to use, but the duplicates will be deleted. As you said, you don't like that. (But it would be easier)

Without deleting and keeping the original array sorting

There you need a new array, with task and the number.

$tasks = array('task1', 'task4', 'task2', 'task3', 'task4', 'task3', 'task4', 'task5');

$numbers = []; // saving the random number, so the same task will get the same number
$result = [];

foreach ($tasks as $task) {
    if (isset($result[$task])) {
        $number = $numbers[$task];
    } else {
        $number = rand(1, 2);
        $numbers[$task] = $number;
    }

    $result[] = [
        'task' => $task,
        'number' => $number,
    ];

    // or $result[] = $number;
    // then only the number is saved at the position of $task
}

result var_dump($result);

array (size=8)
  0 => 
    array (size=2)
      'task' => string 'task1' (length=5)
      'number' => int 2
  1 => 
    array (size=2)
      'task' => string 'task4' (length=5)
      'number' => int 1
  2 => 
    array (size=2)
      'task' => string 'task2' (length=5)
      'number' => int 2
  3 => 
    array (size=2)
      'task' => string 'task3' (length=5)
      'number' => int 2
  4 => 
    array (size=2)
      'task' => string 'task4' (length=5)
      'number' => int 1
  5 => 
    array (size=2)
      'task' => string 'task3' (length=5)
      'number' => int 2
  6 => 
    array (size=2)
      'task' => string 'task4' (length=5)
      'number' => int 1
  7 => 
    array (size=2)
      'task' => string 'task5' (length=5)
      'number' => int 1

Upvotes: 2

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