alireza task

alireza.php

<?php
$string = 'aboozar';
$dic  =   [
    'a' => [1, 2, 'a'],
    'b' => [3, 4, 'b'],
    'o' => [5, 6],
    'z' => [7, 8, 'd', 'f'],
    'r' => [9, 0, 'e']
];

$chars = str_split($string);
$strLen = count($chars) - 1;

$tmp = [];

for ($i = 0; $i <= $strLen; $i++) {
    $options = [];

    $dicRow    = $dic[$chars[$i]];
    $dicRowLen = count($dicRow) - 1;

    if ($i>0) {
        for ($j = 0; $j <= $dicRowLen; $j++) {
            foreach ($tmp as $t) {
                $options[] = $t . $dicRow[$j];
            }
        }

    } else {
        for ($j = 0; $j <= $dicRowLen; $j++) {
            $options[] = $dicRow[$j];
        }
    }
    $tmp = $options;
}

print_r($options);