Merge branch 'master' into lb_add_tests

Author: siriak

DIRECTORY.md

@@ -23,8 +23,14 @@
             * [WordPatternMatcher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/WordPatternMatcher.java)
             * [WordSearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/WordSearch.java)
           * bitmanipulation
+            * [BinaryPalindromeCheck](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/BinaryPalindromeCheck.java)
             * [BitSwap](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/BitSwap.java)
+            * [ClearLeftmostSetBit](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/ClearLeftmostSetBit.java)
+            * [CountLeadingZeros](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/CountLeadingZeros.java)
             * [CountSetBits](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/CountSetBits.java)
+            * [GrayCodeConversion](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/GrayCodeConversion.java)
+            * [HammingDistance](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/HammingDistance.java)
+            * [HigherLowerPowerOfTwo](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/HigherLowerPowerOfTwo.java)
             * [HighestSetBit](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/HighestSetBit.java)
             * [IndexOfRightMostSetBit](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/IndexOfRightMostSetBit.java)
             * [IsEven](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/IsEven.java)
@@ -50,11 +56,13 @@
             * [AES](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/AES.java)
             * [AESEncryption](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/AESEncryption.java)
             * [AffineCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/AffineCipher.java)
+            * [AtbashCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/AtbashCipher.java)
             * [Autokey](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Autokey.java)
             * [Blowfish](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Blowfish.java)
             * [Caesar](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Caesar.java)
             * [ColumnarTranspositionCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/ColumnarTranspositionCipher.java)
             * [DES](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/DES.java)
+            * [ECC](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/ECC.java)
             * [HillCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/HillCipher.java)
             * [PlayfairCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/PlayfairCipher.java)
             * [Polybius](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Polybius.java)
@@ -353,6 +361,7 @@
             * [JosephusProblem](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/JosephusProblem.java)
             * [JugglerSequence](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/JugglerSequence.java)
             * [KaprekarNumbers](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/KaprekarNumbers.java)
+            * [KaratsubaMultiplication](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/KaratsubaMultiplication.java)
             * [KeithNumber](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/KeithNumber.java)
             * [KrishnamurthyNumber](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/KrishnamurthyNumber.java)
             * [LeastCommonMultiple](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/LeastCommonMultiple.java)
@@ -512,6 +521,7 @@
             * [PerfectBinarySearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/PerfectBinarySearch.java)
             * [QuickSelect](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/QuickSelect.java)
             * [RabinKarpAlgorithm](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/RabinKarpAlgorithm.java)
+            * [RandomSearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/RandomSearch.java)
             * [RecursiveBinarySearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/RecursiveBinarySearch.java)
             * [RowColumnWiseSorted2dArrayBinarySearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/RowColumnWiseSorted2dArrayBinarySearch.java)
             * [SaddlebackSearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/searches/SaddlebackSearch.java)
@@ -642,8 +652,14 @@
             * [WordPatternMatcherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/WordPatternMatcherTest.java)
             * [WordSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/WordSearchTest.java)
           * bitmanipulation
+            * [BinaryPalindromeCheckTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/BinaryPalindromeCheckTest.java)
             * [BitSwapTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/BitSwapTest.java)
+            * [ClearLeftmostSetBitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/ClearLeftmostSetBitTest.java)
+            * [CountLeadingZerosTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/CountLeadingZerosTest.java)
             * [CountSetBitsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/CountSetBitsTest.java)
+            * [GrayCodeConversionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/GrayCodeConversionTest.java)
+            * [HammingDistanceTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/HammingDistanceTest.java)
+            * [HigherLowerPowerOfTwoTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/HigherLowerPowerOfTwoTest.java)
             * [HighestSetBitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/HighestSetBitTest.java)
             * [IndexOfRightMostSetBitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/IndexOfRightMostSetBitTest.java)
             * [IsEvenTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/IsEvenTest.java)
@@ -665,11 +681,13 @@
               * [LFSRTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/a5/LFSRTest.java)
             * [AESEncryptionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/AESEncryptionTest.java)
             * [AffineCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/AffineCipherTest.java)
+            * [AtbashTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/AtbashTest.java)
             * [AutokeyTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/AutokeyTest.java)
             * [BlowfishTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/BlowfishTest.java)
             * [CaesarTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/CaesarTest.java)
             * [ColumnarTranspositionCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/ColumnarTranspositionCipherTest.java)
             * [DESTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/DESTest.java)
+            * [ECCTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/ECCTest.java)
             * [HillCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/HillCipherTest.java)
             * [PlayfairTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/PlayfairTest.java)
             * [PolybiusTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/PolybiusTest.java)
@@ -818,6 +836,7 @@
             * [LongestPalindromicSubstringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/LongestPalindromicSubstringTest.java)
             * [LongestValidParenthesesTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/LongestValidParenthesesTest.java)
             * [MatrixChainMultiplicationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/MatrixChainMultiplicationTest.java)
+            * [MatrixChainRecursiveTopDownMemoisationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/MatrixChainRecursiveTopDownMemoisationTest.java)
             * [MaximumSumOfNonAdjacentElementsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/MaximumSumOfNonAdjacentElementsTest.java)
             * [MinimumPathSumTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/MinimumPathSumTest.java)
             * [MinimumSumPartitionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/MinimumSumPartitionTest.java)
@@ -900,6 +919,7 @@
             * [HeronsFormulaTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/HeronsFormulaTest.java)
             * [JosephusProblemTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/JosephusProblemTest.java)
             * [KaprekarNumbersTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/KaprekarNumbersTest.java)
+            * [KaratsubaMultiplicationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/KaratsubaMultiplicationTest.java)
             * [LeastCommonMultipleTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/LeastCommonMultipleTest.java)
             * [LeonardoNumberTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/LeonardoNumberTest.java)
             * [LiouvilleLambdaFunctionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/LiouvilleLambdaFunctionTest.java)
@@ -984,6 +1004,7 @@
             * [RemoveDuplicateFromStringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/RemoveDuplicateFromStringTest.java)
             * [ReverseStackUsingRecursionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/ReverseStackUsingRecursionTest.java)
             * [SkylineProblemTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/SkylineProblemTest.java)
+            * [SudokuTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/SudokuTest.java)
             * [TestPrintMatrixInSpiralOrder](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/TestPrintMatrixInSpiralOrder.java)
             * [TwoPointersTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/TwoPointersTest.java)
             * [WorstFitCPUTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/WorstFitCPUTest.java)
@@ -1021,6 +1042,7 @@
             * [PerfectBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/PerfectBinarySearchTest.java)
             * [QuickSelectTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/QuickSelectTest.java)
             * [RabinKarpAlgorithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/RabinKarpAlgorithmTest.java)
+            * [RandomSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/RandomSearchTest.java)
             * [RecursiveBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/RecursiveBinarySearchTest.java)
             * [RowColumnWiseSorted2dArrayBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/RowColumnWiseSorted2dArrayBinarySearchTest.java)
             * [SaddlebackSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/SaddlebackSearchTest.java)

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

@@ -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/ClearLeftmostSetBit.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/CountLeadingZeros.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/GrayCodeConversion.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/HammingDistance.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);
+    }
+}