Merge branch 'master' into count_inversions_new_algo

Author: siriak

DIRECTORY.md

@@ -23,6 +23,7 @@
             * [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
+            * [BcdConversion](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/BcdConversion.java)
             * [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)
             * [BooleanAlgebraGates](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/BooleanAlgebraGates.java)
@@ -48,6 +49,7 @@
             * [SingleElement](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/SingleElement.java)
             * [SwapAdjacentBits](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/SwapAdjacentBits.java)
             * [TwosComplement](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/TwosComplement.java)
+            * [Xs3Conversion](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/Xs3Conversion.java)
           * ciphers
             * a5
               * [A5Cipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/a5/A5Cipher.java)
@@ -92,6 +94,7 @@
             * [HexToOct](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/HexToOct.java)
             * [IntegerToEnglish](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/IntegerToEnglish.java)
             * [IntegerToRoman](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/IntegerToRoman.java)
+            * [IPConverter](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/IPConverter.java)
             * [OctalToBinary](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/OctalToBinary.java)
             * [OctalToDecimal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/OctalToDecimal.java)
             * [OctalToHexadecimal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/OctalToHexadecimal.java)
@@ -502,7 +505,9 @@
             * [FCFSScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/FCFSScheduling.java)
             * [HighestResponseRatioNextScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/HighestResponseRatioNextScheduling.java)
             * [JobSchedulingWithDeadline](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/JobSchedulingWithDeadline.java)
+            * [LotteryScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/LotteryScheduling.java)
             * [MLFQScheduler](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/MLFQScheduler.java)
+            * [NonPreemptivePriorityScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/NonPreemptivePriorityScheduling.java)
             * [PreemptivePriorityScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/PreemptivePriorityScheduling.java)
             * [RRScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/RRScheduling.java)
             * [SJFScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/SJFScheduling.java)
@@ -597,7 +602,9 @@
             * [MaximumMinimumWindow](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/MaximumMinimumWindow.java)
             * [NextGreaterElement](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/NextGreaterElement.java)
             * [NextSmallerElement](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/NextSmallerElement.java)
+            * [PostfixEvaluator](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/PostfixEvaluator.java)
             * [PostfixToInfix](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/PostfixToInfix.java)
+            * [PrefixEvaluator](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/PrefixEvaluator.java)
             * [PrefixToInfix](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/PrefixToInfix.java)
             * [SortStack](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/SortStack.java)
             * [StackPostfixNotation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/stacks/StackPostfixNotation.java)
@@ -660,6 +667,7 @@
             * [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
+            * [BcdConversionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/BcdConversionTest.java)
             * [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)
             * [BooleanAlgebraGatesTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/BooleanAlgebraGatesTest.java)
@@ -685,6 +693,7 @@
             * [SingleElementTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/SingleElementTest.java)
             * [SwapAdjacentBitsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/SwapAdjacentBitsTest.java)
             * [TwosComplementTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/TwosComplementTest.java)
+            * [Xs3ConversionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/Xs3ConversionTest.java)
           * ciphers
             * a5
               * [A5CipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/a5/A5CipherTest.java)
@@ -722,6 +731,7 @@
             * [HexToOctTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/HexToOctTest.java)
             * [IntegerToEnglishTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/IntegerToEnglishTest.java)
             * [IntegerToRomanTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/IntegerToRomanTest.java)
+            * [IPConverterTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/IPConverterTest.java)
             * [OctalToBinaryTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/OctalToBinaryTest.java)
             * [OctalToDecimalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/OctalToDecimalTest.java)
             * [OctalToHexadecimalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/OctalToHexadecimalTest.java)
@@ -1022,6 +1032,7 @@
             * [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)
+            * [TowerOfHanoiTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/TowerOfHanoiTest.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)
           * Recursion
@@ -1031,7 +1042,9 @@
             * [FCFSSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/FCFSSchedulingTest.java)
             * [HighestResponseRatioNextSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/HighestResponseRatioNextSchedulingTest.java)
             * [JobSchedulingWithDeadlineTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/JobSchedulingWithDeadlineTest.java)
+            * [LotterySchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/LotterySchedulingTest.java)
             * [MLFQSchedulerTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/MLFQSchedulerTest.java)
+            * [NonPreemptivePrioritySchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/NonPreemptivePrioritySchedulingTest.java)
             * [PreemptivePrioritySchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/PreemptivePrioritySchedulingTest.java)
             * [RRSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/RRSchedulingTest.java)
             * [SJFSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/SJFSchedulingTest.java)
@@ -1125,7 +1138,9 @@
             * [LargestRectangleTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/LargestRectangleTest.java)
             * [NextGreaterElementTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/NextGreaterElementTest.java)
             * [NextSmallerElementTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/NextSmallerElementTest.java)
+            * [PostfixEvaluatorTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/PostfixEvaluatorTest.java)
             * [PostfixToInfixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/PostfixToInfixTest.java)
+            * [PrefixEvaluatorTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/PrefixEvaluatorTest.java)
             * [PrefixToInfixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/PrefixToInfixTest.java)
             * [SortStackTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/SortStackTest.java)
             * [StackPostfixNotationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/stacks/StackPostfixNotationTest.java)

checkstyle.xml

@@ -183,7 +183,7 @@
     <!-- See https://checkstyle.org/checks/misc/index.html -->
     <module name="ArrayTypeStyle"/>
     <!-- TODO <module name="FinalParameters"/> -->
-    <!-- TODO <module name="TodoComment"/> -->
+    <module name="TodoComment"/>
     <module name="UpperEll"/>
 
     <!-- https://checkstyle.org/filters/suppressionxpathfilter.html -->

pom.xml

@@ -40,6 +40,13 @@
             <version>${assertj.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>5.14.1</version>
+            <scope>test</scope>
+        </dependency>
+
 
         <dependency>
             <groupId>org.junit.jupiter</groupId>

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

@@ -0,0 +1,82 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * This class provides methods to convert between BCD (Binary-Coded Decimal) and decimal numbers.
+ *
+ * BCD is a class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of binary digits, usually four or eight.
+ *
+ * For more information, refer to the
+ * <a href="https://en.wikipedia.org/wiki/Binary-coded_decimal">Binary-Coded Decimal</a> Wikipedia page.
+ *
+ * <b>Example usage:</b>
+ * <pre>
+ * int decimal = BcdConversion.bcdToDecimal(0x1234);
+ * System.out.println("BCD 0x1234 to decimal: " + decimal); // Output: 1234
+ *
+ * int bcd = BcdConversion.decimalToBcd(1234);
+ * System.out.println("Decimal 1234 to BCD: " + Integer.toHexString(bcd)); // Output: 0x1234
+ * </pre>
+ */
+public final class BcdConversion {
+    private BcdConversion() {
+    }
+
+    /**
+     * Converts a BCD (Binary-Coded Decimal) number to a decimal number.
+     * <p>Steps:
+     * <p>1. Validate the BCD number to ensure all digits are between 0 and 9.
+     * <p>2. Extract the last 4 bits (one BCD digit) from the BCD number.
+     * <p>3. Multiply the extracted digit by the corresponding power of 10 and add it to the decimal number.
+     * <p>4. Shift the BCD number right by 4 bits to process the next BCD digit.
+     * <p>5. Repeat steps 1-4 until the BCD number is zero.
+     *
+     * @param bcd The BCD number.
+     * @return The corresponding decimal number.
+     * @throws IllegalArgumentException if the BCD number contains invalid digits.
+     */
+    public static int bcdToDecimal(int bcd) {
+        int decimal = 0;
+        int multiplier = 1;
+
+        // Validate BCD digits
+        while (bcd > 0) {
+            int digit = bcd & 0xF;
+            if (digit > 9) {
+                throw new IllegalArgumentException("Invalid BCD digit: " + digit);
+            }
+            decimal += digit * multiplier;
+            multiplier *= 10;
+            bcd >>= 4;
+        }
+        return decimal;
+    }
+
+    /**
+     * Converts a decimal number to BCD (Binary-Coded Decimal).
+     * <p>Steps:
+     * <p>1. Check if the decimal number is within the valid range for BCD (0 to 9999).
+     * <p>2. Extract the last decimal digit from the decimal number.
+     * <p>3. Shift the digit to the correct BCD position and add it to the BCD number.
+     * <p>4. Remove the last decimal digit from the decimal number.
+     * <p>5. Repeat steps 2-4 until the decimal number is zero.
+     *
+     * @param decimal The decimal number.
+     * @return The corresponding BCD number.
+     * @throws IllegalArgumentException if the decimal number is greater than 9999.
+     */
+    public static int decimalToBcd(int decimal) {
+        if (decimal < 0 || decimal > 9999) {
+            throw new IllegalArgumentException("Value out of bounds for BCD representation: " + decimal);
+        }
+
+        int bcd = 0;
+        int shift = 0;
+        while (decimal > 0) {
+            int digit = decimal % 10;
+            bcd |= (digit << (shift * 4));
+            decimal /= 10;
+            shift++;
+        }
+        return bcd;
+    }
+}

src/main/java/com/thealgorithms/bitmanipulation/Xs3Conversion.java

@@ -0,0 +1,58 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * This class provides methods to convert between XS-3 (Excess-3) and binary.
+ *
+ * Excess-3, also called XS-3, is a binary-coded decimal (BCD) code in which each decimal digit is represented by its corresponding 4-bit binary value plus 3.
+ *
+ * For more information, refer to the
+ * <a href="https://en.wikipedia.org/wiki/Excess-3">Excess-3</a> Wikipedia page.
+ *
+ * <b>Example usage:</b>
+ * <pre>
+ * int binary = Xs3Conversion.xs3ToBinary(0x4567);
+ * System.out.println("XS-3 0x4567 to binary: " + binary); // Output: 1234
+ *
+ * int xs3 = Xs3Conversion.binaryToXs3(1234);
+ * System.out.println("Binary 1234 to XS-3: " + Integer.toHexString(xs3)); // Output: 0x4567
+ * </pre>
+ */
+public final class Xs3Conversion {
+    private Xs3Conversion() {
+    }
+    /**
+     * Converts an XS-3 (Excess-3) number to binary.
+     *
+     * @param xs3 The XS-3 number.
+     * @return The corresponding binary number.
+     */
+    public static int xs3ToBinary(int xs3) {
+        int binary = 0;
+        int multiplier = 1;
+        while (xs3 > 0) {
+            int digit = (xs3 & 0xF) - 3; // Extract the last 4 bits (one XS-3 digit) and subtract 3
+            binary += digit * multiplier;
+            multiplier *= 10;
+            xs3 >>= 4; // Shift right by 4 bits to process the next XS-3 digit
+        }
+        return binary;
+    }
+
+    /**
+     * Converts a binary number to XS-3 (Excess-3).
+     *
+     * @param binary The binary number.
+     * @return The corresponding XS-3 number.
+     */
+    public static int binaryToXs3(int binary) {
+        int xs3 = 0;
+        int shift = 0;
+        while (binary > 0) {
+            int digit = (binary % 10) + 3; // Extract the last decimal digit and add 3
+            xs3 |= (digit << (shift * 4)); // Shift the digit to the correct XS-3 position
+            binary /= 10; // Remove the last decimal digit
+            shift++;
+        }
+        return xs3;
+    }
+}

src/main/java/com/thealgorithms/conversions/IPConverter.java

@@ -0,0 +1,58 @@
+package com.thealgorithms.conversions;
+
+/**
+ * Converts an IPv4 address to its binary equivalent and vice-versa.
+ * IP to Binary: Converts an IPv4 address to its binary equivalent.
+ * Example: 127.3.4.5 -> 01111111.00000011.00000100.00000101
+ *
+ * Binary to IP: Converts a binary equivalent to an IPv4 address.
+ * Example: 01111111.00000011.00000100.00000101 -> 127.3.4.5
+ *
+ * @author Hardvan
+ */
+public final class IPConverter {
+    private IPConverter() {
+    }
+
+    /**
+     * Converts an IPv4 address to its binary equivalent.
+     * @param ip The IPv4 address to convert.
+     * @return The binary equivalent of the IPv4 address.
+     */
+    public static String ipToBinary(String ip) {
+        StringBuilder binary = new StringBuilder();
+        for (String octet : ip.split("\\.")) {
+            binary.append(octetToBinary(Integer.parseInt(octet))).append(".");
+        }
+        return binary.substring(0, binary.length() - 1);
+    }
+
+    /**
+     * Converts a single octet to its 8-bit binary representation.
+     * @param octet The octet to convert (0-255).
+     * @return The 8-bit binary representation as a String.
+     */
+    private static String octetToBinary(int octet) {
+        char[] binary = {'0', '0', '0', '0', '0', '0', '0', '0'};
+        for (int i = 7; i >= 0; i--) {
+            if ((octet & 1) == 1) {
+                binary[i] = '1';
+            }
+            octet >>>= 1;
+        }
+        return new String(binary);
+    }
+
+    /**
+     * Converts a binary equivalent to an IPv4 address.
+     * @param binary The binary equivalent to convert.
+     * @return The IPv4 address of the binary equivalent.
+     */
+    public static String binaryToIP(String binary) {
+        StringBuilder ip = new StringBuilder();
+        for (String octet : binary.split("\\.")) {
+            ip.append(Integer.parseInt(octet, 2)).append(".");
+        }
+        return ip.substring(0, ip.length() - 1);
+    }
+}