Find element with duplicate key value and add new key using PHP - php

Question

I have an array
$info = array(
[0] => array(
'id' => 1,
'uid' => '677674e21aed487fd7180da4a7619a9d'
),
[1] => array(
'id' => 1,
'uid' => 'd3c98a10fe4e42fb1fe868008c0f4cc1'
),
[2] => array(
'id' => 1,
'uid' => 'd3c98a10fe4e42fb1fe868008c0f4cc1'
),
[3] => array(
'id' => 1,
'uid' => '658284e5395a29bf34d21f30a854e965'
),
[4] => array(
'id' => 1,
'uid' => '01f33ae45a463e0c1de4ad989b3ccad5'
),
[5] => array(
'id' => 1,
'uid' => '677674e21aed487fd7180da4a7619a9d'
)
)
As you can see, uid of 0th index and 5th index are same. Similarly, uid of 2nd index and 3rd index are same.
I want a PHP script by which I can randomly create one hexadecimal color code for duplicate uids. Say something like this.
$info = array(
[0] => array(
'id' => 1,
'uid' => '677674e21aed487fd7180da4a7619a9d',
'col' => 'black'
),
[1] => array(
'id' => 1,
'uid' => 'd3c98a10fe4e42fb1fe868008c0f4cc1',
'col' => 'green'
),
[2] => array(
'id' => 1,
'uid' => 'd3c98a10fe4e42fb1fe868008c0f4cc1',
'col' => 'green'
),
[3] => array(
'id' => 1,
'uid' => '658284e5395a29bf34d21f30a854e965'
),
[4] => array(
'id' => 1,
'uid' => '01f33ae45a463e0c1de4ad989b3ccad5'
),
[5] => array(
'id' => 1,
'uid' => '677674e21aed487fd7180da4a7619a9d',
'col' => 'black'
)
)
How can I do this with the most minimum execution time?

Answer 1

There might be various ways for doing this workout, but due to lack of proper response, I came up with this probable lengthier code. I am posting the answer here for people who might need this.
$uidArray = array(); // creating a blank array to feed each uid
$uidDuplicateArray = array(); // creating a blank array as container to hold duplicate uid(s) only
foreach($all_data as $key => $ad)
{
// iterate through each item of the list
/.................
.................. //
$uidArray[] = $ad['uid'];
}
foreach(array_count_values($uidArray) as $val => $c)
{
if($c > 1)
{
// if count value is more than 1, then its duplicate
// set the uid duplicate array with key as uid and unique color code as value
$uidDuplicateArray[$val] = sprintf('#%06X', mt_rand(0, 0xFFFFFF));
}
}
foreach($all_data as $keyAgain => $adg)
{
// iterating through each item of original data
if(isset($uidDuplicateArray[$adg['uid']]))
{
// if the uid is key of the duplicate array, feed the value to original array in a new key.
$all_data[$keyAgain]['color'] = $uidDuplicateArray[$adg['uid']];
}
}
Each comment associated with each LOC is self explanatory.
The reason I wanted this, is to mark the duplicates in UI like this:-