Merge branch 'master' into power2_new_algo

Author: siriak

.github/workflows/build.yml

@@ -10,7 +10,7 @@ jobs:
         uses: actions/setup-java@v4
         with:
           java-version: 21
-          distribution: 'adopt'
+          distribution: 'temurin'
       - name: Build with Maven
         run: mvn --batch-mode --update-snapshots verify
       - name: Upload coverage to codecov (tokenless)

.github/workflows/codeql.yml

@@ -30,7 +30,7 @@ jobs:
         uses: actions/setup-java@v4
         with:
           java-version: 21
-          distribution: 'adopt'
+          distribution: 'temurin'
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v3

.github/workflows/infer.yml

@@ -18,7 +18,7 @@ jobs:
         uses: actions/setup-java@v4
         with:
           java-version: 21
-          distribution: 'adopt'
+          distribution: 'temurin'
 
       - name: Set up OCaml
         uses: ocaml/setup-ocaml@v3

DIRECTORY.md

@@ -0,0 +1,43 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * This class contains a method to check if the binary representation of a number is a palindrome.
+ * <p>
+ *     A binary palindrome is a number whose binary representation is the same when read from left to right and right to left.
+ *     For example, the number 9 has a binary representation of 1001, which is a palindrome.
+ *     The number 10 has a binary representation of 1010, which is not a palindrome.
+ * </p>
+ *
+ * @author Hardvan
+ */
+public final class BinaryPalindromeCheck {
+    private BinaryPalindromeCheck() {
+    }
+
+    /**
+     * Checks if the binary representation of a number is a palindrome.
+     *
+     * @param x The number to check.
+     * @return True if the binary representation is a palindrome, otherwise false.
+     */
+    public static boolean isBinaryPalindrome(int x) {
+        int reversed = reverseBits(x);
+        return x == reversed;
+    }
+
+    /**
+     * Helper function to reverse all the bits of an integer.
+     *
+     * @param x The number to reverse the bits of.
+     * @return The number with reversed bits.
+     */
+    private static int reverseBits(int x) {
+        int result = 0;
+        while (x > 0) {
+            result <<= 1;
+            result |= (x & 1);
+            x >>= 1;
+        }
+        return result;
+    }
+}

src/main/java/com/thealgorithms/bitmanipulation/BinaryPalindromeCheck.java

@@ -0,0 +1,39 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * ClearLeftmostSetBit class contains a method to clear the leftmost set bit of a number.
+ * The leftmost set bit is the leftmost bit that is set to 1 in the binary representation of a number.
+ *
+ * Example:
+ * 26 (11010) -> 10 (01010)
+ * 1 (1) -> 0 (0)
+ * 7 (111) -> 3 (011)
+ * 6 (0110) -> 2 (0010)
+ *
+ * @author Hardvan
+ */
+public final class ClearLeftmostSetBit {
+    private ClearLeftmostSetBit() {
+    }
+
+    /**
+     * Clears the leftmost set bit (1) of a given number.
+     * Step 1: Find the position of the leftmost set bit
+     * Step 2: Create a mask with all bits set except for the leftmost set bit
+     * Step 3: Clear the leftmost set bit using AND with the mask
+     *
+     * @param num The input number.
+     * @return The number after clearing the leftmost set bit.
+     */
+    public static int clearLeftmostSetBit(int num) {
+        int pos = 0;
+        int temp = num;
+        while (temp > 0) {
+            temp >>= 1;
+            pos++;
+        }
+
+        int mask = ~(1 << (pos - 1));
+        return num & mask;
+    }
+}

src/main/java/com/thealgorithms/bitmanipulation/ClearLeftmostSetBit.java

@@ -0,0 +1,39 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * CountLeadingZeros class contains a method to count the number of leading zeros in the binary representation of a number.
+ * The number of leading zeros is the number of zeros before the leftmost 1 bit.
+ * For example, the number 5 has 29 leading zeros in its 32-bit binary representation.
+ * The number 0 has 32 leading zeros.
+ * The number 1 has 31 leading zeros.
+ * The number -1 has no leading zeros.
+ *
+ * @author Hardvan
+ */
+public final class CountLeadingZeros {
+    private CountLeadingZeros() {
+    }
+
+    /**
+     * Counts the number of leading zeros in the binary representation of a number.
+     * Method: Keep shifting the mask to the right until the leftmost bit is 1.
+     * The number of shifts is the number of leading zeros.
+     *
+     * @param num The input number.
+     * @return The number of leading zeros.
+     */
+    public static int countLeadingZeros(int num) {
+        if (num == 0) {
+            return 32;
+        }
+
+        int count = 0;
+        int mask = 1 << 31;
+        while ((mask & num) == 0) {
+            count++;
+            mask >>>= 1;
+        }
+
+        return count;
+    }
+}

src/main/java/com/thealgorithms/bitmanipulation/CountLeadingZeros.java

@@ -0,0 +1,44 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * Gray code is a binary numeral system where two successive values differ in only one bit.
+ * This is a simple conversion between binary and Gray code.
+ * Example:
+ * 7 -> 0111 -> 0100 -> 4
+ * 4 -> 0100 -> 0111 -> 7
+ * 0 -> 0000 -> 0000 -> 0
+ * 1 -> 0001 -> 0000 -> 0
+ * 2 -> 0010 -> 0011 -> 3
+ * 3 -> 0011 -> 0010 -> 2
+ *
+ * @author Hardvan
+ */
+public final class GrayCodeConversion {
+    private GrayCodeConversion() {
+    }
+
+    /**
+     * Converts a binary number to Gray code.
+     *
+     * @param num The binary number.
+     * @return The corresponding Gray code.
+     */
+    public static int binaryToGray(int num) {
+        return num ^ (num >> 1);
+    }
+
+    /**
+     * Converts a Gray code number back to binary.
+     *
+     * @param gray The Gray code number.
+     * @return The corresponding binary number.
+     */
+    public static int grayToBinary(int gray) {
+        int binary = gray;
+        while (gray > 0) {
+            gray >>= 1;
+            binary ^= gray;
+        }
+        return binary;
+    }
+}

src/main/java/com/thealgorithms/bitmanipulation/GrayCodeConversion.java

@@ -0,0 +1,29 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * The Hamming distance between two integers is the number of positions at which the corresponding bits are different.
+ * Given two integers x and y, calculate the Hamming distance.
+ * Example:
+ * Input: x = 1, y = 4
+ * Output: 2
+ * Explanation: 1 (0001) and 4 (0100) have 2 differing bits.
+ *
+ * @author Hardvan
+ */
+public final class HammingDistance {
+    private HammingDistance() {
+    }
+
+    /**
+     * Calculates the Hamming distance between two integers.
+     * The Hamming distance is the number of differing bits between the two integers.
+     *
+     * @param x The first integer.
+     * @param y The second integer.
+     * @return The Hamming distance (number of differing bits).
+     */
+    public static int hammingDistance(int x, int y) {
+        int xor = x ^ y;
+        return Integer.bitCount(xor);
+    }
+}

src/main/java/com/thealgorithms/bitmanipulation/HammingDistance.java

@@ -0,0 +1,71 @@
+package com.thealgorithms.ciphers;
+
+/**
+ * The Atbash cipher is a simple substitution cipher that replaces each letter
+ * in the alphabet with its reverse.
+ * For example, 'A' becomes 'Z', 'B' becomes 'Y', and so on. It works
+ * identically for both uppercase and lowercase letters.
+ * It's a symmetric cipher, meaning applying it twice returns the original text.
+ * Hence, the encrypting and the decrypting functions are identical
+ * @author https://github.com/Krounosity
+ * Learn more: https://en.wikipedia.org/wiki/Atbash
+ */
+
+public class AtbashCipher {
+
+    private String toConvert;
+
+    // Default constructor.
+    AtbashCipher() {
+    }
+
+    // String setting constructor.
+    AtbashCipher(String str) {
+        toConvert = str;
+    }
+
+    // String getter method.
+    public String getString() {
+        return toConvert;
+    }
+
+    // String setter method.
+    public void setString(String str) {
+        toConvert = str;
+    }
+
+    // Checking whether the current character is capital.
+    private boolean isCapital(char ch) {
+        return ch >= 'A' && ch <= 'Z';
+    }
+
+    // Checking whether the current character is smallcased.
+    private boolean isSmall(char ch) {
+        return ch >= 'a' && ch <= 'z';
+    }
+
+    // Converting text to atbash cipher code or vice versa.
+    public String convert() {
+
+        // Using StringBuilder to store new string.
+        StringBuilder convertedString = new StringBuilder();
+
+        // Iterating for each character.
+        for (char ch : toConvert.toCharArray()) {
+
+            // If the character is smallcased.
+            if (isSmall(ch)) {
+                convertedString.append((char) ('z' - (ch - 'a')));
+            }
+            // If the character is capital cased.
+            else if (isCapital(ch)) {
+                convertedString.append((char) ('Z' - (ch - 'A')));
+            }
+            // Non-alphabetical character.
+            else {
+                convertedString.append(ch);
+            }
+        }
+        return convertedString.toString();
+    }
+}