diff --git a/DIRECTORY.md b/DIRECTORY.md index 3692b436a353..b62cde038651 100644 --- a/DIRECTORY.md +++ b/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 + * [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) @@ -650,6 +651,7 @@ * [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 + * [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) diff --git a/src/main/java/com/thealgorithms/bitmanipulation/BinaryPalindromeCheck.java b/src/main/java/com/thealgorithms/bitmanipulation/BinaryPalindromeCheck.java new file mode 100644 index 000000000000..0d6fd140c720 --- /dev/null +++ b/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. + *
+ * 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. + *
+ * + * @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; + } +} diff --git a/src/test/java/com/thealgorithms/bitmanipulation/BinaryPalindromeCheckTest.java b/src/test/java/com/thealgorithms/bitmanipulation/BinaryPalindromeCheckTest.java new file mode 100644 index 000000000000..ff41344266e4 --- /dev/null +++ b/src/test/java/com/thealgorithms/bitmanipulation/BinaryPalindromeCheckTest.java @@ -0,0 +1,18 @@ +package com.thealgorithms.bitmanipulation; + +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertTrue; + +import org.junit.jupiter.api.Test; + +public class BinaryPalindromeCheckTest { + + @Test + public void testIsBinaryPalindrome() { + assertTrue(BinaryPalindromeCheck.isBinaryPalindrome(9)); // 1001 is a palindrome + assertFalse(BinaryPalindromeCheck.isBinaryPalindrome(10)); // 1010 is not a palindrome + assertTrue(BinaryPalindromeCheck.isBinaryPalindrome(0)); // 0 is a palindrome + assertTrue(BinaryPalindromeCheck.isBinaryPalindrome(1)); // 1 is a palindrome + assertFalse(BinaryPalindromeCheck.isBinaryPalindrome(12)); // 1100 is not a palindrome + } +}