function isPalindrome($word)
{
echo "{$word}\n";
$wordLength = strlen($word);
echo "word length: {$wordLength}\n";
$midPoint = (int) ceil($wordLength / 2) - 1;
$midPointLetter = $word[$midPoint];
echo "mid point index: {$midPoint}, {$midPointLetter}\n";
$prevLetters = array();
for ($currLetIdx = 0; $currLetIdx < $wordLength; $currLetIdx++) {
$currentLetter = $word[$currLetIdx];
$prevLetters[] = $currentLetter;
$comparisonIndex = $wordLength - ($currLetIdx + 1);
if ($currLetIdx > $midPoint) {
echo "current index:" . $currLetIdx . "\n";
echo "current letter:" . $currentLetter . "\n";
echo "comparison index:" . $comparisonIndex . "\n";
echo "comparison letter:" . $prevLetters[$comparisonIndex] . "\n";
}
if ($currLetIdx > $midPoint && $currentLetter != $prevLetters[$comparisonIndex]) {
echo "stopping ...\n";
return false;
}
}
return true;
}
$palindromes = array('noon', 'civic', 'reviver', 'word', 'racecar', 'redder');
foreach ($palindromes as $palindrome) {
var_dump(isPalindrome($palindrome));
echo "\n";
}
<?php
/**
* Largest palindrome product
* https://projecteuler.net/problem=4
*/
require '../show_answer.php';
$startTime = microtime(true);
$palindroms = [];
for ($i = 100; $i <= 999; $i++) {
for ($j = $i; $j <= 999; $j++) {
$production = $i * $j;
if (isPalindrome($production)) {
$palindroms[] = $production;
}
}
}
$result = max($palindroms);
showAnswer($result, $startTime);
function isPalindrome($value)
{
return $value == strrev($value);
}
//we join the letters with s space between them
}
function shuffleStr($str)
{
$arrChars = str_split($str);
shuffle($arrChars);
$shuffledStr = implode('', $arrChars);
return $shuffledStr;
}
if (isset($_POST['submit'])) {
if (isset($_POST['radios']) && isset($_POST['str'])) {
$case = $_POST['radios'];
$str = $_POST['str'];
switch ($case) {
case "0":
echo isPalindrome($str) ? $str . " is a palindrome!" : $str . " is not a palindrome!";
break;
case '1':
echo strrev($str);
break;
case '2':
echo splitStr($str);
break;
case '3':
echo crypt($str, strrev($str));
break;
case '4':
echo shuffleStr($str);
break;
}
} else {
<?php
$message = $_POST['message'];
echo "Vneseno besedilo: " . $message . "<br><br>";
if (isPalindrome($message) == true) {
echo '"Vneseno besedilo JE PALINDROM"';
} else {
echo ' Vneseno besedilo ni NI PLANINDROM ';
}
// funkcija - preveri ali je vneseno besedilo palindrom
function isPalindrome($message)
{
// odstarni presledke iz besedila
$input = stristr(' ', $message);
// preveri ali se besedilo brez presledkov bere enako naprej kot nazaj
if ($input == strrev($input)) {
return true;
} else {
return false;
}
}
function isPalindrome($string)
{
if (substr($string, 0, 1) == substr($string, strlen($string) - 1, 1)) {
if (strlen($string) > 3) {
return isPalindrome(substr($string, 1, strlen($string) - 2));
} else {
return true;
}
} else {
return false;
}
}
function q36($max)
{
$sum = 0;
for ($i = 0; $i < $max; ++$i) {
$base2 = base_convert($i, 10, 2);
$base10 = (string) $i;
$isPalindromeInBase2 = isPalindrome($base2);
$isPalindromeInBase10 = isPalindrome($base10);
if ($isPalindromeInBase2 && $isPalindromeInBase10) {
$sum += $i;
}
}
return $sum;
}
/**
* Checks if a string is a palindrome.
*
* @param {string} $text - The text to test.
* @return {boolean} true if $text is a palindrome, false otherwise.
*/
function isPalindrome($text)
{
// Let's cache the string length since we are using it more than once.
$len = mb_strlen($text);
// Matches rule 1.
if ($len <= 1) {
return true;
}
// Matches rule 2a.
if (mb_substr($text, 0, 1) !== mb_substr($text, $len - 1, 1)) {
return false;
}
// Matches rule 2b. Recursive invokes itself to verify rules 1 and 2a.
return isPalindrome(mb_substr(1, $len - 2));
}
function largestPalindrome()
{
$lastProduct = 0;
for ($i = 999; $i > 0; $i--) {
for ($j = 999; $j > 0; $j--) {
$thisProduct = $i * $j;
if (isPalindrome($thisProduct)) {
if ($thisProduct < $lastProduct) {
break 2;
} else {
$lastProduct = $thisProduct;
}
}
}
}
return $lastProduct;
}
function largestPalindrome($max = 999, $min = 100)
{
$maxPalindrome = 0;
for ($i = $max; $i > $min; $i--) {
// To avoid checking both a*b and b*a, we assume one number is smaller
// than the other
for ($j = $max; $j > $i; $j--) {
$product = $i * $j;
// Early break if the product is already smaller than the max Pal
if ($product < $maxPalindrome) {
break;
}
if (isPalindrome($product)) {
$maxPalindrome = max($maxPalindrome, $product);
}
}
}
echo $maxPalindrome;
}
function getPalindrome($str)
{
if (isPalindrome($str)) {
return $str;
}
$palLen = 1;
$palText = mb_substr($str, 0, 1, "UTF-8");
$stLen = mb_strlen($str, "UTF-8");
for ($i = 0; $i < $stLen; $i++) {
for ($j = $i + 1; $j <= $stLen - 1; $j++) {
$part = trim(mb_substr($str, $i, $j - $i + 1, "UTF-8"));
$partLen = isPalindrome($part);
if ($partLen > $palLen) {
$palLen = $partLen;
$palText = $part;
}
}
}
return $palText;
}
и
Всем пока
Перенос строк чому-то тут не работает тоже :c
EOF
;
echo $bigText;
echo mb_strlen($bigText);
*/
$textPalindrome = "А роза упала на лапу Азора";
$textNonPalindrome = "Я совсем не палиндром";
function isPalindrome($string)
{
$string = str_replace(" ", "", mb_strtolower($string));
/*
* $ebuchka = 1; ты была хорошим другом, ебучка.
*/
for ($i = 0; $i <= floor(mb_strlen($string) / 2); $i++) {
if (mb_substr($string, $i - 1, 1) != mb_substr($string, -$i, 1)) {
return false;
break;
}
}
return true;
}
echo isPalindrome($textNonPalindrome);
echo "<br>";
echo isPalindrome($textPalindrome);
echo "<br>";
case 'reverse':
$output = strrev($str);
break;
case 'split':
$letters = [];
preg_match_all('/[a-zA-Z]/', $str, $letters);
$output = implode(' ', $letters[0]);
break;
case 'hash':
$output = crypt($str, 'defsalt');
break;
case 'shuffle':
$output = str_shuffle($str);
break;
default:
$output = isPalindrome($str) ? $str . ' is palindrome!' : $str . ' is not a palindrome!';
break;
}
}
?>
<!DOCTYPE html>
<html>
<head>
<title>Modify String</title>
</head>
<body>
<form>
<input type="text" name="inputString">
<input type="radio" name="op" value="isPalindrome" id="isPalindrome" checked>
<label for="isPalindrome">Check Palindrome</label>
<input type="radio" name="op" value="reverse" id="reverse">
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*
*
*/
function isPalindrome($n)
{
return strrev($n) == $n ? true : false;
}
$result = "";
for ($i = 100; $i <= 999; $i++) {
for ($j = 100; $j <= 999; $j++) {
if (isPalindrome($i * $j)) {
$result = $i . ", " . $j . " = " . $i * $j;
}
}
}
echo $result . "\n";
$lastIndex = $len - 1;
$result = true;
if ($len % 2 == 0) {
//if even
$halfLen = $len / 2;
for ($i = 0; $i < $halfLen; $i++) {
if ($str[$i] == $str[$lastIndex - $i]) {
$result = $result && true;
} else {
$result = $result && false;
}
}
return $result;
} else {
//if odd
$halfLen = floor($len / 2);
for ($i = 0; $i < $halfLen; $i++) {
if ($str[$i] == $str[$lastIndex - $i]) {
$result = $result && true;
} else {
$result = $result && false;
}
}
return $result;
}
}
var_dump(isPalindrome('mom'));
var_dump(isPalindrome('hannah'));
var_dump(isPalindrome('not a palindrome'));
var_dump(isPalindrome('really not a palindrome'));
// modifies it according to the selected option (radio button). You should support the following
// operations: palindrome check, reverse string, split to extract leters only, hash the string
// with the default PHP hashing algorithm, shuffle the string characters randomly. The result
// should be displayed right under the input field. Styling the page is optional. Think about
// which of the modification can be achieved with already built-in functions in PHP.
// Where necessary, write your own algorithms to modify the given string. Hint: Use the crypt()
// function for the "Hash String" modification.
header("Content-Type: text/html; charset=utf8");
require './functions.php';
if (!empty($_POST['user-input'])) {
$string = htmlentities($_POST['user-input']);
$selection = htmlentities($_POST['option']);
$result = '';
switch ($selection) {
case 'palindrome':
if (isPalindrome($string)) {
$result = "{$string} is a palindrome!";
} else {
$result = "{$string} is not a palindrome!";
}
break;
case "shuffle":
$result = str_shuffle($string);
break;
case "reverse":
$result = reverse($string);
break;
case "hash":
$result = password_hash($string, PASSWORD_BCRYPT);
break;
case "split":
<?php
function isPalindrome($word)
{
$word = strtolower(str_replace(" ", "", $word));
$stack = new SplStack();
$cnt = strlen($word);
for ($i = 0; $i < $cnt; ++$i) {
$stack->push($word[$i]);
}
$rword = "";
while ($stack->count() > 0) {
$rword .= $stack->pop();
}
return $word == $rword;
}
$word = "hello";
if (isPalindrome($word)) {
print $word . " is a palindrome.\n";
} else {
print $word . " is not a palindrome.\n";
}
if (isset($_POST['string'], $_POST['option'])) {
function isPalindrome($string)
{
$a = strtolower(preg_replace("/[^A-Za-z0-9]/", "", $string));
return $a == strrev($a);
}
function splitLetters($string)
{
$letters = preg_replace('/[^A-Za-z]/', '', $string);
return implode(' ', str_split($letters));
}
$string = $_POST['string'];
$option = $_POST['option'];
switch ($option) {
case "Check Palindrome":
$output = "'{$string}' is " . (isPalindrome($string) ? "a palindrome." : "not a palindrome!");
break;
case "Reverse String":
$output = strrev($string);
break;
case "Split":
$output = splitLetters($string);
break;
case "Hash String":
$output = crypt($string);
break;
case "Shuffle String":
$output = str_shuffle($string);
break;
}
?>
/*
* Задача 8:
Да се състави програма, чрез която се въвежда ред от символи
(стринг, низ).
Програмата да изведе на екрана дали въведения стринг е палиндром,
т.е. дали четен отляво-надясно и отдясно-наляво е един и същ.
Вход: капак
Изход: да.
Вход: тенджера
Изход: не.
*/
require_once 'readline.php';
//require_once 'functions.php';с
function isPalindrome(&$string)
{
$reverseString = strrev($string);
$stringToCompare = md5($string);
$reverseStringToCompare = md5($reverseString);
if (strcmp($stringToCompare, $reverseStringToCompare) == 0) {
return true;
} else {
return false;
}
}
$input = readline('Enter some string: ');
$result = isPalindrome($input);
if ($result) {
echo 'Yes!';
} else {
echo 'No!';
}
*/
/**
* Palindromes
* racecar
*
* take a string, identify if palindrome or not
*
* Also do other homework
*/
function isPalindrome($word)
{
$wordLength = strlen($word);
$lastIndex = $wordLength - 1;
$k = $lastIndex;
$reverse = "";
for ($i = 0; $i <= $lastIndex; $i++) {
$reverse = $reverse . $word[$k];
$k = $k - 1;
}
if ($word == $reverse) {
echo $word . ' is palindrome';
} else {
echo $word . ' is not palindrome';
}
}
echo isPalindrome('abba');
echo '<br>';
echo isPalindrome('qwertyuiopl');
echo '<br>';
echo isPalindrome('racecar');
<?php
$min = 100;
$max = 999;
$palindromes = [];
for ($i = $max; $i >= $min; $i--) {
for ($j = $max; $j >= $min; $j--) {
$product = $i * $j;
if (isPalindrome($product)) {
$palindromes[] = $product;
}
}
}
sort($palindromes);
var_dump(end($palindromes));
function isPalindrome($number)
{
$string = (string) $number;
if (strrev($string) == $string) {
return true;
}
return false;
}
require_once "../functionExLib.php";
?>
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<form method="POST">
Input String to see if it is a palindrome:
<input type="text" name="input" autofocus />
<input type="submit" value="Submit" />
</form>
<?php
if (isset($_POST['input'])) {
print isPalindrome($_POST['input']) . "<br />";
}
?>
<!-- put a button on the form to reset it -->
<a href="<?php
echo $_SERVER['PHP_SELF'];
?>
">Reset</a>
<?php
?>
</body>
</html>
<?php
/**
* Largest palindrome product
*
* A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.
* Find the largest palindrome made from the product of two 3-digit numbers.
*/
$largest_3digit_nr = 999;
$largest_3digit_nr_2nd = 999;
$palindromes = array();
$largest_palindrome = 0;
for ($i = $largest_3digit_nr; $i >= 100; $i--) {
for ($y = $largest_3digit_nr_2nd; $y >= 100; $y--) {
if (isPalindrome($i * $y)) {
$palindromes[] = $i * $y;
}
}
}
$largest_palindrome = max($palindromes);
echo $largest_palindrome;
function isPalindrome($number)
{
$number_array = array();
$number_length = strlen($number);
if ($number_length < 2) {
return true;
} else {
for ($i = 0; $i < $number_length; $i++) {
$last_digit = $number % 10;
$number = floor($number / 10);
<?php
require_once '../functions.php';
$nums1 = $nums2 = range(999, 100);
$wanted = 0;
foreach ($nums1 as $num1) {
foreach ($nums2 as $num2) {
$num = $num1 * $num2;
if (isPalindrome($num) && $num > $wanted) {
$wanted = $num;
}
}
}
echo $wanted;
<?php
// duncaneuler36.php
$start = microtime(true);
$sum = 0;
function isPalindrome($x)
{
return $x == strrev($x);
}
for ($i = 1; $i <= 999999; $i++) {
if (isPalindrome($i) && isPalindrome(decbin($i))) {
echo $i . " " . decbin($i) . "<br>";
$sum += $i;
}
}
echo $sum . "<hr>";
$end = microtime(true);
printf("Execution time: %dms", ($end - $start) * 1000);
<?php
class Palindrome
{
public static function isPalindrome($str)
{
throw new Exception('Not implemented');
}
}
// TESTE
echo isPalindrome('A grama e amarga.');
