[getting started] extract non repeating integers

describe

Enter a int Type integer , Read right to left , Returns a new integer with no repeating numbers . Ensure that the last bit of the input integer is not 0 .

Input description

Enter a int Type integer

Output description

Read right to left , Returns a new integer with no repeating numbers

Example 1

Input ：9876673
Output ：37689

<?php
fscanf(STDIN, "%d", $a);
//  To string 
$a .= "";
//  Result string 
$res = '';
//  String length 
$len = strlen($a);

for ($i = $len - 1; $i > -1; $i--) {
    
    if (strpos($res, $a[$i]) !== false) {
    
        continue;
    }
    $res .= $a[$i];
}
echo $res;