diff --git a/DIRECTORY.md b/DIRECTORY.md index 15f91de16..10922d761 100644 --- a/DIRECTORY.md +++ b/DIRECTORY.md @@ -31,6 +31,7 @@ * [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) * [FindNthBit](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/FindNthBit.java) + * [FirstDifferentBit](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/FirstDifferentBit.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) @@ -727,6 +728,7 @@ * [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) * [FindNthBitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/FindNthBitTest.java) + * [FirstDifferentBitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/FirstDifferentBitTest.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) diff --git a/src/main/java/com/thealgorithms/bitmanipulation/FirstDifferentBit.java b/src/main/java/com/thealgorithms/bitmanipulation/FirstDifferentBit.java new file mode 100644 index 000000000..9a761c572 --- /dev/null +++ b/src/main/java/com/thealgorithms/bitmanipulation/FirstDifferentBit.java @@ -0,0 +1,33 @@ +package com.thealgorithms.bitmanipulation; + +/** + * This class provides a method to find the first differing bit + * between two integers. + * + * Example: + * x = 10 (1010 in binary) + * y = 12 (1100 in binary) + * The first differing bit is at index 1 (0-based) + * So, the output will be 1 + * + * @author Hardvan + */ +public final class FirstDifferentBit { + private FirstDifferentBit() { + } + + /** + * Identifies the index of the first differing bit between two integers. + * Steps: + * 1. XOR the two integers to get the differing bits + * 2. Find the index of the first set bit in XOR result + * + * @param x the first integer + * @param y the second integer + * @return the index of the first differing bit (0-based) + */ + public static int firstDifferentBit(int x, int y) { + int diff = x ^ y; + return Integer.numberOfTrailingZeros(diff); + } +} diff --git a/src/test/java/com/thealgorithms/bitmanipulation/FirstDifferentBitTest.java b/src/test/java/com/thealgorithms/bitmanipulation/FirstDifferentBitTest.java new file mode 100644 index 000000000..ae7bad9a6 --- /dev/null +++ b/src/test/java/com/thealgorithms/bitmanipulation/FirstDifferentBitTest.java @@ -0,0 +1,15 @@ +package com.thealgorithms.bitmanipulation; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +import org.junit.jupiter.params.ParameterizedTest; +import org.junit.jupiter.params.provider.CsvSource; + +public class FirstDifferentBitTest { + + @ParameterizedTest + @CsvSource({"10, 8, 1", "7, 5, 1", "15, 14, 0", "1, 2, 0"}) + void testFirstDifferentBit(int x, int y, int expected) { + assertEquals(expected, FirstDifferentBit.firstDifferentBit(x, y)); + } +}