How to find the maximum sequence of characters at the end of an array that are the same as the beginning of the array?

Question

I want to write code that finds the maximum sequence of characters at the end of an array that are the same as the beginning of the array.

But I dont know how I can do it with PHP?

For example:

Input = [a,b,c,e,r,t,x,s,b,a,b,c] 
Output = [a,b,c]

(because the elements a,b,c are both at the beginning and end of the array and they represent the maximum sequence of such characters)

Answer 1

Note: This will work perfectly for this kind of array, where we have array of strings, it does not work for nested array.

Try this code snippet here

<?php
ini_set('display_errors', 1);
$data  = array("a","b","c","e","r","t","x","s","b","a","b","c"); 
$string=  implode("", $data);//converting array to string.
for($x=strlen($string)-1;$x>=0;$x--)
{
    //matching substring from the end of string.
    if(preg_match("/".substr($string, 0,$x)."$/",$string)==true)
    {
        $string= substr($string, 0,$x);
        break;
    }
}
$result=str_split($string);
print_r($result);