Casi Palindromes

palindrome.php

<?php 

define('NECESARY_CHANGES', 3);

/** 
 * @param string $string
 * @return bool
 */
function palindrome($string) {
    $revert = strrev($string);
    $length = strlen($string);

    return $length > 1 && (levenshtein($string, $revert) < NECESARY_CHANGES);
}

/**
 * @test 
 */
function testPalindrome(array $words)
{
    foreach($words as $word) {
        if (palindrome($word)) {
            echo "it is almost palindrome \n";            
        } else {
            echo "failure: the word: " . $word . " is not palindrome \n";
        }        
    }
}

$words = ['reconocer', 'oso', 'arepera', 'osao', 'hola'];
testPalindrome($words);