From 966b4e369dc5a8097e3ee0ff16b5fdd91c187d8a Mon Sep 17 00:00:00 2001 From: Hardik Pawar <97388607+Hardvan@users.noreply.github.com> Date: Sat, 12 Oct 2024 11:30:12 +0530 Subject: [PATCH] feat: Add ClearLeftmostSetBit new algorithm with Junit tests (#5702) --- DIRECTORY.md | 5 +++ .../bitmanipulation/ClearLeftmostSetBit.java | 39 +++++++++++++++++++ .../ClearLeftmostSetBitTest.java | 16 ++++++++ 3 files changed, 60 insertions(+) create mode 100644 src/main/java/com/thealgorithms/bitmanipulation/ClearLeftmostSetBit.java create mode 100644 src/test/java/com/thealgorithms/bitmanipulation/ClearLeftmostSetBitTest.java diff --git a/DIRECTORY.md b/DIRECTORY.md index d0f50b421..51af99583 100644 --- a/DIRECTORY.md +++ b/DIRECTORY.md @@ -24,6 +24,7 @@ * [WordSearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/WordSearch.java) * bitmanipulation * [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) * [CountSetBits](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/CountSetBits.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) @@ -355,6 +356,7 @@ * [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) @@ -646,6 +648,7 @@ * [WordSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/WordSearchTest.java) * bitmanipulation * [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) * [CountSetBitsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/CountSetBitsTest.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) @@ -905,6 +908,7 @@ * [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) @@ -989,6 +993,7 @@ * [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) diff --git a/src/main/java/com/thealgorithms/bitmanipulation/ClearLeftmostSetBit.java b/src/main/java/com/thealgorithms/bitmanipulation/ClearLeftmostSetBit.java new file mode 100644 index 000000000..3e9a4a211 --- /dev/null +++ b/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; + } +} diff --git a/src/test/java/com/thealgorithms/bitmanipulation/ClearLeftmostSetBitTest.java b/src/test/java/com/thealgorithms/bitmanipulation/ClearLeftmostSetBitTest.java new file mode 100644 index 000000000..e77889fb7 --- /dev/null +++ b/src/test/java/com/thealgorithms/bitmanipulation/ClearLeftmostSetBitTest.java @@ -0,0 +1,16 @@ +package com.thealgorithms.bitmanipulation; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +import org.junit.jupiter.api.Test; + +public class ClearLeftmostSetBitTest { + + @Test + public void testClearLeftmostSetBit() { + assertEquals(10, ClearLeftmostSetBit.clearLeftmostSetBit(26)); // 11010 -> 01010 + assertEquals(0, ClearLeftmostSetBit.clearLeftmostSetBit(1)); // 1 -> 0 + assertEquals(3, ClearLeftmostSetBit.clearLeftmostSetBit(7)); // 111 -> 011 + assertEquals(2, ClearLeftmostSetBit.clearLeftmostSetBit(6)); // 0110 -> 0010 + } +}