Merge branch 'master' into add/ciphers/xor_cipher

.github/workflows/ci.yml

@@ -0,0 +1,34 @@
+name: PHP Composer
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Validate composer.json and composer.lock
+      run: composer validate
+
+    - name: Cache Composer packages
+      id: composer-cache
+      uses: actions/cache@v2
+      with:
+        path: vendor
+        key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
+        restore-keys: |
+          ${{ runner.os }}-php-
+
+    - name: Install dependencies
+      if: steps.composer-cache.outputs.cache-hit != 'true'
+      run: composer install --prefer-dist --no-progress --no-suggest
+
+    - name: Run PHPUnit
+      run: composer run-script test

CONTRIBUTING.md

@@ -12,7 +12,7 @@ We are very happy that you would consider contributing! As a contributor, you ag
 
 - You did your work - no plagiarism allowed
   - Any plagiarized work will not be merged
-- Your work will be distributed under [MIT License](License) once your pull request is merged
+- Your work will be distributed under [MIT License](LICENSE) once your pull request is merged
 - Your submitted work follows (or mostly follows) the styles and standards already found in this repo
 
 **New implementations** are welcome! For example, new solutions for an existing problem, different representations for a graph data structure or an algorithm design with different complexity.

DIRECTORY.md

@@ -1,4 +1,5 @@
 ## Ciphers
+  * [Caesar Cipher](https://github.com/TheAlgorithms/PHP/blob/master/ciphers/caesarCipher.php)
   * [Xor Cipher](https://github.com/TheAlgorithms/PHP/blob/master/ciphers/XORCipher.php)
   
 ## Searching

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020 The Algorithms
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Maths/AbsoluteMax.php

@@ -0,0 +1,25 @@
+<?php
+/**
+ * This function calculates
+ * Absolute max values from
+ * the different numbers
+ * provided
+ *
+ * @param decimal $numbers A variable sized number input
+ * @return decimal $absoluteMax Absolute max value
+ */
+function absolute_max(...$numbers)
+{
+    if (empty($numbers)) {
+        throw new \Exception('Please pass values to find absolute max value');
+    }
+
+    $absoluteMax = $numbers[0];
+    for ($loopIndex = 0; $loopIndex < count($numbers); $loopIndex++) {
+        if ($numbers[$loopIndex] > $absoluteMax) {
+            $absoluteMax = $numbers[$loopIndex];
+        }
+    }
+
+    return $absoluteMax;
+}

Maths/AbsoluteMin.php

@@ -0,0 +1,25 @@
+<?php
+/**
+ * This function calculates
+ * Absolute min values from
+ * the different numbers
+ * provided.
+ *
+ * @param decimal $numbers A variable sized number input
+ * @return decimal $absoluteMin Absolute min value
+ */
+function absolute_min(...$numbers)
+{
+    if (empty($numbers)) {
+        throw new \Exception('Please pass values to find absolute min value');
+    }
+
+    $absoluteMin = $numbers[0];
+    for ($loopIndex = 0; $loopIndex < count($numbers); $loopIndex++) {
+        if ($numbers[$loopIndex] < $absoluteMin) {
+            $absoluteMin = $numbers[$loopIndex];
+        }
+    }
+
+    return $absoluteMin;
+}

Maths/CheckPrime.php

@@ -0,0 +1,29 @@
+<?php
+/**
+ * This function check whether
+ * the provided integer is a prime
+ * number or not.
+ *
+ * @param Integer $number An integer input
+ * @return boolean whether the number is prime or not
+ */
+function isPrime(int $number)
+{
+    if ($number === 2) {
+        return true;
+    }
+
+    if ($number % 2 === 0 or $number < 2) {
+        return false;
+    }
+
+    $i = 3;
+    while ($i < sqrt($number)) {
+        if ($number % $i === 0) {
+            return false;
+        }
+        $i += 2;
+    }
+
+    return true;
+}

Maths/Factorial.php

@@ -0,0 +1,20 @@
+<?php
+/**
+ * This function calculates
+ * and returns the factorial
+ * of provided positive integer
+ * number.
+ *
+ * @param Integer $number Integer input
+ * @return Integer Factorial of the input
+ */
+function factorial(int $number)
+{
+    if ($number < 0) {
+        throw new \Exception("Negative numbers are not allowed for calculating Factorial");
+    }
+    if ($number === 0) {
+        return 1; // Factorial of 0 is 1
+    }
+    return ($number * factorial($number - 1)); // Recursion since x! = x * (x-1)!
+}

Maths/PerfectSquare.php

@@ -0,0 +1,14 @@
+<?php
+/**
+ * This function check whether
+ * the provided number is a
+ * perfect square or not.
+ *
+ * @param Decimal $number A decimal input
+ * @return boolean whether the number is perfect square or not
+ */
+function is_perfect_square($number)
+{
+    $root = (int) sqrt($number);
+    return (($root * $root) === $number); // If number's square root is an integer then it's a perfect square else not
+}

ciphers/caesarCipher.php

@@ -0,0 +1,52 @@
+<?php
+
+/**
+ * Encrypt given text using caesar cipher.
+ * @param string text text to be encrypted
+ * @param int shift number of shifts to be applied
+ * @return string new encrypted text
+ */
+function encrypt(string $text, int $shift): string
+{
+    $encryptedText = ''; // Empty string to store encrypted text
+    foreach (str_split($text) as $c) { // Going through each character
+        if (ctype_alpha($c)) {
+            $placeValue = ord($c) - ord(ctype_upper($c) ? 'A' : 'a'); // Getting value of character (i.e. 0-25)
+            $placeValue = ($placeValue + $shift) % 26; // Applying encryption formula
+            $placeValue += ord(ctype_upper($c) ? 'A' : 'a');
+            $newChar = chr($placeValue); // Getting new character from new value (i.e. A-Z)
+            $encryptedText .= $newChar; // Appending encrypted character
+        } else {
+            $encryptedText .= $c; // Appending the original character
+        }
+    }
+
+    return $encryptedText; // Returning encrypted text
+}
+
+/**
+ * Decrypt given text using caesar cipher.
+ * @param string text text to be decrypted
+ * @param int shift number of shifts to be applied
+ * @return string new decrypted text
+ */
+function decrypt(string $text, int $shift): string
+{
+    $decryptedText = ''; // Empty string to store decrypted text
+    foreach (str_split($text) as $c) { // Going through each character
+        if (ctype_alpha($c)) {
+            $placeValue = ord($c) - ord(ctype_upper($c) ? 'A' : 'a'); // Getting value of character (i.e. 0-25)
+            $placeValue = ($placeValue - $shift) % 26; // Applying decryption formula
+            if ($placeValue < 0) { // Handling case where remainder is negative 
+                $placeValue += 26;
+            }
+            $placeValue += ord(ctype_upper($c) ? 'A' : 'a');
+            $newChar = chr($placeValue); // Getting new character from new value (i.e. A-Z)
+            $decryptedText .= $newChar; // Appending decrypted character
+        } else {
+            $decryptedText .= $c; // Appending the original character
+        }
+    }
+
+    return $decryptedText; // Returning decrypted text
+}

composer.json

@@ -1,8 +1,14 @@
 {
+	"name" : "thealgorithms/php",
+	"description": "All Algorithms implemented in PHP",
+	"license": "MIT",
 	"require": {
 		"phan/phan": "^2.7"
 	},
 	"require-dev": {
 		"phpunit/phpunit": "^9"
+	},
+	"scripts": {
+		"test": "vendor/bin/phpunit tests"
 	}
 }

tests/CiphersTest.php

@@ -0,0 +1,18 @@
+<?php
+
+use function PHPUnit\Framework\assertEquals;
+use PHPUnit\Framework\TestCase;
+
+require_once __DIR__ . '/../vendor/autoload.php';
+require_once __DIR__ . '/../ciphers/caesarCipher.php';
+
+class CiphersTest extends TestCase
+{
+    public function testCaesarCipher()
+    {
+        assertEquals('Aopz pz h alza.', encrypt('This is a test.', 7));
+        assertEquals('Aopz pz h alza.', encrypt('This is a test.', 7 + 26));
+        assertEquals('This is a test.', decrypt('Aopz pz h alza.', 7));
+        assertEquals('This is a test.', decrypt('Aopz pz h alza.', 7 + 26));
+    }
+}

tests/MathTest.php

@@ -0,0 +1,59 @@
+<?php
+
+use function PHPUnit\Framework\assertEquals;
+use function PHPUnit\Framework\assertFalse;
+use function PHPUnit\Framework\assertTrue;
+use PHPUnit\Framework\TestCase;
+
+require_once __DIR__ . '/../vendor/autoload.php';
+require_once __DIR__ . '/../Maths/Factorial.php';
+require_once __DIR__ . '/../Maths/CheckPrime.php';
+require_once __DIR__ . '/../Maths/AbsoluteMax.php';
+require_once __DIR__ . '/../Maths/AbsoluteMin.php';
+require_once __DIR__ . '/../Maths/PerfectSquare.php';
+
+class MathTest extends TestCase
+{
+    public function testFactorial()
+    {
+        assertEquals(1, factorial(1));
+        assertEquals(120, factorial(5));
+        assertEquals(1, factorial(0));
+        $this->expectException(\Exception::class);
+        factorial(-25);
+    }
+
+    public function testIsPrime()
+    {
+        assertTrue(isPrime(73));
+        assertFalse(isPrime(21));
+        assertFalse(isPrime(1));
+        assertTrue(isPrime(997));
+    }
+
+    public function testAbsoluteMax()
+    {
+        assertEquals(50, absolute_max(12, 20, 35, 50, 50, 23));
+        assertEquals(13, absolute_max(13));
+        assertEquals(54, absolute_max(12, 13, 54, 22));
+        $this->expectException(\Exception::class);
+        absolute_max();
+    }
+
+    public function testAbsoluteMin()
+    {
+        assertEquals(12, absolute_min(12, 20, 35, 50, 50, 23));
+        assertEquals(13, absolute_min(13));
+        assertEquals(12, absolute_min(12, 13, 54, 22));
+        $this->expectException(\Exception::class);
+        absolute_min();
+    }
+
+    public function testPerfectSquare()
+    {
+        assertTrue(is_perfect_square(25));
+        assertFalse(is_perfect_square(43));
+        assertFalse(is_perfect_square(2));
+        assertTrue(is_perfect_square(225));
+    }
+}