Merge branch 'master' into SentinelSearch

.github/workflows/ci.yml

@@ -12,14 +12,20 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '7.4'
+          ini-values: xdebug.max_nesting_level=512
 
       - name: Validate composer.json and composer.lock
         run: composer validate
 
       - name: Cache Composer packages
         id: composer-cache
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: vendor
           key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}

.github/workflows/code-style.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2

.github/workflows/directory_workflow.yml

@@ -8,12 +8,12 @@ jobs:
     name: DIRECTORY.md
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1 # v2 is broken for git diff
-      - uses: actions/setup-python@v2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
       - name: Setup Git Specs
         run: |
-          git config --global user.name github-actions
-          git config --global user.email '${GITHUB_ACTOR}@users.noreply.github.com'
+          git config --global user.name "$GITHUB_ACTOR"
+          git config --global user.email "$[email protected]"
           git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/$GITHUB_REPOSITORY
       - name: Update DIRECTORY.md
         shell: python

.gitpod.Dockerfile

@@ -0,0 +1 @@
+FROM gitpod/workspace-full:2022-05-08-14-31-53

.gitpod.yml

@@ -0,0 +1,6 @@
+image:
+    file: .gitpod.Dockerfile
+
+tasks:
+  - init: |
+      echo "Welcome to TheAlgorithms/PHP"

Ciphers/AtbashCipher.php

@@ -0,0 +1,39 @@
+<?php
+
+/**
+ * Encrypt a message using the Atbash Cipher.
+ * The Atbash Cipher is a simple substitution cipher where each letter in the plaintext is
+ * replaced with its corresponding letter from the end of the alphabet (reverse alphabet).
+ * Non-alphabet characters are not modified.
+ *
+ * @param string $plainText The plaintext to encrypt.
+ * @return string The encrypted message.
+ */
+function atbash_encrypt($plainText)
+{
+    $result = '';
+    $plainText = strtoupper($plainText);
+    for ($i = 0; $i < strlen($plainText); $i++) {
+        $char = $plainText[$i];
+        if (ctype_alpha($char)) {
+            $offset = ord('Z') - ord($char);
+            $encryptedChar = chr(ord('A') + $offset);
+        } else {
+            $encryptedChar = $char; // Non-alphabet characters remain unchanged
+        }
+        $result .= $encryptedChar;
+    }
+    return $result;
+}
+
+/**
+ * Decrypt a message encrypted using the Atbash Cipher.
+ * Since the Atbash Cipher is its own inverse, decryption is the same as encryption.
+ *
+ * @param string $cipherText The ciphertext to decrypt.
+ * @return string The decrypted message.
+ */
+function atbash_decrypt($cipherText)
+{
+    return atbash_encrypt($cipherText); // Decryption is the same as encryption
+}

Ciphers/RailfenceCipher.php

@@ -0,0 +1,81 @@
+<?php
+
+/**
+ * Encode a message using the Rail Fence Cipher.
+ * (https://en.wikipedia.org/wiki/Rail_fence_cipher)
+ *
+ * @param string $plainMessage The message to encode.
+ * @param int $rails The number of rails or rows in the rail fence.
+ *
+ * @return string The encoded message.
+ */
+function Railencode($plainMessage, $rails): string
+{
+    $cipherMessage = [];
+    $position = ($rails * 2) - 2;
+    // Iterate through the characters of the plain message
+    for ($index = 0; $index < strlen($plainMessage); $index++) {
+        for ($step = 0; $step < $rails; $step++) {
+            if (!isset($cipherMessage[$step])) {
+                $cipherMessage[$step] = '';
+            }
+            // Check if the character should go in the rail
+            if ($index % $position == $step || $index % $position == $position - $step) {
+                $cipherMessage[$step] .= $plainMessage[$index];
+            } else {
+                // Add a placeholder for empty spaces
+                $cipherMessage[$step] .= ".";
+            }
+        }
+    }
+    // Combine and remove placeholders to form the cipher message
+    return implode('', str_replace('.', '', $cipherMessage));
+}
+
+/**
+ * Decode a message encoded using the Rail Fence Cipher.
+ *
+ * @param string $cipherMessage The encoded message.
+ * @param int $rails The number of rails or rows used for encoding.
+ *
+ * @return string The decoded plain message.
+ */
+function Raildecode($cipherMessage, $rails): string
+{
+    $position = ($rails * 2) - 2;
+    $textLength = strlen($cipherMessage);
+    $minLength = floor($textLength / $position);
+    $balance = $textLength % $position;
+    $lengths = [];
+    $strings = [];
+    $totalLengths = 0;
+    // Calculate the number of characters in each row
+    for ($rowIndex = 0; $rowIndex < $rails; $rowIndex++) {
+        $lengths[$rowIndex] = $minLength;
+        if ($rowIndex != 0 && $rowIndex != ($rails - 1)) {
+            $lengths[$rowIndex] += $minLength;
+        }
+        if ($balance > $rowIndex) {
+            $lengths[$rowIndex]++;
+        }
+        if ($balance > ($rails + ($rails - $rowIndex) - 2)) {
+            $lengths[$rowIndex]++;
+        }
+        $strings[] = substr($cipherMessage, $totalLengths, $lengths[$rowIndex]);
+        $totalLengths += $lengths[$rowIndex];
+    }
+    // Convert the rows of characters to plain message
+    $plainText = '';
+    while (strlen($plainText) < $textLength) {
+        for ($charIndex = 0; $charIndex < $position; $charIndex++) {
+            if (isset($strings[$charIndex])) {
+                $index = $charIndex;
+            } else {
+                $index = $position - $charIndex;
+            }
+            $plainText .= substr($strings[$index], 0, 1);
+            $strings[$index] = substr($strings[$index], 1);
+        }
+    }
+    return $plainText;
+}

Ciphers/VignereCipher.php

@@ -0,0 +1,63 @@
+<?php
+
+/**
+ * Encrypts a plaintext using the Vigenère cipher.
+ * (https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher)
+ *
+ * @param string $plaintext The plaintext to be encrypted.
+ * @param string $key The encryption key.
+ * @return string The encrypted text.
+ */
+function vigenere_encrypt($plaintext, $key): string
+{
+    // Convert the input to uppercase for consistency
+    $plaintext = strtoupper($plaintext);
+    $key = strtoupper($key);
+    $keyLength = strlen($key);
+    $encryptedText = "";
+    for ($i = 0; $i < strlen($plaintext); $i++) {
+        $char = $plaintext[$i];
+        if (ctype_alpha($char)) {
+            // Calculate the shift based on the key
+            $shift = ord($key[$i % $keyLength]) - ord('A');
+            // Apply the Vigenère encryption formula
+            $encryptedChar = chr(((ord($char) - ord('A') + $shift) % 26) + ord('A'));
+            // Append the encrypted character to the result
+            $encryptedText .= $encryptedChar;
+        } else {
+            // If the character is not alphabetic, leave it unchanged
+            $encryptedText .= $char;
+        }
+    }
+    return $encryptedText;
+}
+
+/**
+ * Decrypts a ciphertext using the Vigenère cipher.
+ *
+ * @param string $ciphertext The ciphertext to be decrypted.
+ * @param string $key The decryption key.
+ * @return string The decrypted text.
+ */
+function vigenere_decrypt($ciphertext, $key): string
+{
+    $ciphertext = strtoupper($ciphertext);
+    $key = strtoupper($key);
+    $keyLength = strlen($key);
+    $decryptedText = "";
+    for ($i = 0; $i < strlen($ciphertext); $i++) {
+        $char = $ciphertext[$i];
+        if (ctype_alpha($char)) {
+            // Calculate the shift based on the key
+            $shift = ord($key[$i % $keyLength]) - ord('A');
+            // Apply the Vigenère decryption formula
+            $decryptedChar = chr(((ord($char) - ord('A') - $shift + 26) % 26) + ord('A'));
+            // Append the decrypted character to the result
+            $decryptedText .= $decryptedChar;
+        } else {
+            // If the character is not alphabetic, leave it unchanged
+            $decryptedText .= $char;
+        }
+    }
+    return $decryptedText;
+}

DIRECTORY.md

@@ -1,9 +1,12 @@
 # List of all files
 
 ## Ciphers
+  * [Atbashcipher](./Ciphers/AtbashCipher.php)
   * [Caesarcipher](./Ciphers/CaesarCipher.php)
   * [Monoalphabeticcipher](./Ciphers/MonoAlphabeticCipher.php)
   * [Morsecode](./Ciphers/MorseCode.php)
+  * [Railfencecipher](./Ciphers/RailfenceCipher.php)
+  * [Vignerecipher](./Ciphers/VignereCipher.php)
   * [Xorcipher](./Ciphers/XORCipher.php)
 
 ## Conversions
@@ -14,22 +17,29 @@
   * [Speedconversion](./Conversions/SpeedConversion.php)
 
 ## Datastructures
+  * [Doublylinkedlist](./DataStructures/DoublyLinkedList.php)
+  * [Node](./DataStructures/Node.php)
   * [Singlylinkedlist](./DataStructures/SinglyLinkedList.php)
+  * [Stack](./DataStructures/Stack.php)
 
 ## Graphs
+  * [Bellmanford](./Graphs/BellmanFord.php)
   * [Breadthfirstsearch](./Graphs/BreadthFirstSearch.php)
   * [Depthfirstsearch](./Graphs/DepthFirstSearch.php)
 
 ## Maths
   * [Absolutemax](./Maths/AbsoluteMax.php)
   * [Absolutemin](./Maths/AbsoluteMin.php)
   * [Armstrongnumber](./Maths/ArmstrongNumber.php)
+  * [Basex](./Maths/BaseX.php)
   * [Checkpalindrome](./Maths/CheckPalindrome.php)
   * [Checkprime](./Maths/CheckPrime.php)
   * [Factorial](./Maths/Factorial.php)
   * [Fastexponentiation](./Maths/FastExponentiation.php)
+  * [Fastinversesquareroot](./Maths/FastInverseSquareRoot.php)
   * [Fibonacci](./Maths/Fibonacci.php)
   * [Fibonacci2](./Maths/Fibonacci2.php)
+  * [Greatestcommondivisor](./Maths/GreatestCommonDivisor.php)
   * [Mean](./Maths/Mean.php)
   * [Median](./Maths/Median.php)
   * [Mode](./Maths/Mode.php)
@@ -58,6 +68,7 @@
   * [Lowerbound](./Searches/LowerBound.php)
   * [SentinelSearch](./Searches/SentinelSearch.php)
   * [Ternarysearch](./Searches/TernarySearch.php)
+  * [Twopointers](./Searches/TwoPointers.php)
   * [Upperbound](./Searches/UpperBound.php)
 
 
@@ -79,6 +90,7 @@
   * [Checkpalindrome](./Strings/CheckPalindrome.php)
   * [Checkpalindrome2](./Strings/CheckPalindrome2.php)
   * [Countconsonants](./Strings/CountConsonants.php)
+  * [Counthomogenous](./Strings/CountHomogenous.php)
   * [Countsentences](./Strings/CountSentences.php)
   * [Countvowels](./Strings/CountVowels.php)
   * [Distance](./Strings/Distance.php)
@@ -88,14 +100,20 @@
 
 ## Tests
   * Ciphers
+    * [Atbashciphertest](./tests/Ciphers/AtbashCipherTest.php)
     * [Cipherstest](./tests/Ciphers/CiphersTest.php)
     * [Monoalphabeticciphertest](./tests/Ciphers/MonoAlphabeticCipherTest.php)
     * [Morsecodetest](./tests/Ciphers/MorseCodeTest.php)
+    * [Railfenceciphertest](./tests/Ciphers/RailfenceCipherTest.php)
+    * [Vignereciphertest](./tests/Ciphers/VignereCipherTest.php)
   * Conversions
     * [Conversionstest](./tests/Conversions/ConversionsTest.php)
   * Datastructures
+    * [Doublylinkedlisttest](./tests/DataStructures/DoublyLinkedListTest.php)
     * [Singlylinkedlisttest](./tests/DataStructures/SinglyLinkedListTest.php)
+    * [Stacktest](./tests/DataStructures/StackTest.php)
   * Graphs
+    * [Bellmanfordtest](./tests/Graphs/BellmanFordTest.php)
     * [Breadthfirstsearchtest](./tests/Graphs/BreadthFirstSearchTest.php)
     * [Depthfirstsearchtest](./tests/Graphs/DepthFirstSearchTest.php)
   * Maths
@@ -106,7 +124,7 @@
   * Sorting
     * [Arraykeyssorttest](./tests/Sorting/ArrayKeysSortTest.php)
     * [Gnomesorttest](./tests/Sorting/GnomeSortTest.php)
-    * [Sortingtests](./tests/Sorting/SortingTests.php)
+    * [Sortingtest](./tests/Sorting/SortingTest.php)
   * Strings
     * [Stringstest](./tests/Strings/StringsTest.php)