diff --git a/src/main/java/com/thealgorithms/bitmanipulation/FindNthBit.java b/src/main/java/com/thealgorithms/bitmanipulation/FindNthBit.java new file mode 100644 index 000000000000..7a35fc3feebf --- /dev/null +++ b/src/main/java/com/thealgorithms/bitmanipulation/FindNthBit.java @@ -0,0 +1,46 @@ +package com.thealgorithms.bitmanipulation; + +/** + * A utility class to find the Nth bit of a given number. + * + *

This class provides a method to extract the value of the Nth bit (either 0 or 1) + * from the binary representation of a given integer. + * + *

Example: + *

{@code
+ * int result = FindNthBit.findNthBit(5, 2); // returns 0 as the 2nd bit of 5 (binary 101) is 0.
+ * }
+ * + *

Author: Tuhinm2002 + */ +public final class FindNthBit { + + /** + * Private constructor to prevent instantiation. + * + *

This is a utility class, and it should not be instantiated. + * Attempting to instantiate this class will throw an UnsupportedOperationException. + */ + private FindNthBit() { + throw new UnsupportedOperationException("Utility class"); + } + + /** + * Finds the value of the Nth bit of the given number. + * + *

This method uses bitwise operations to extract the Nth bit from the + * binary representation of the given integer. + * + * @param num the integer number whose Nth bit is to be found + * @param n the bit position (1-based) to retrieve + * @return the value of the Nth bit (0 or 1) + * @throws IllegalArgumentException if the bit position is less than 1 + */ + public static int findNthBit(int num, int n) { + if (n < 1) { + throw new IllegalArgumentException("Bit position must be greater than or equal to 1."); + } + // Shifting the number to the right by (n - 1) positions and checking the last bit + return (num & (1 << (n - 1))) >> (n - 1); + } +} diff --git a/src/test/java/com/thealgorithms/bitmanipulation/FindNthBitTest.java b/src/test/java/com/thealgorithms/bitmanipulation/FindNthBitTest.java new file mode 100644 index 000000000000..978003d21358 --- /dev/null +++ b/src/test/java/com/thealgorithms/bitmanipulation/FindNthBitTest.java @@ -0,0 +1,39 @@ +package com.thealgorithms.bitmanipulation; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +import java.util.stream.Stream; +import org.junit.jupiter.params.ParameterizedTest; +import org.junit.jupiter.params.provider.Arguments; +import org.junit.jupiter.params.provider.MethodSource; + +public final class FindNthBitTest { + + /** + * A parameterized test that checks the value of the Nth bit for different inputs. + * + * @param num the number whose Nth bit is being tested + * @param n the bit position + * @param expected the expected value of the Nth bit (0 or 1) + */ + @ParameterizedTest + @MethodSource("provideTestCases") + void findNthBitParameterizedTest(int num, int n, int expected) { + assertEquals(expected, FindNthBit.findNthBit(num, n)); + } + + /** + * Provides the test cases as a stream of arguments for the parameterized test. + * + * @return a stream of test cases where each case consists of a number, the bit position, + * and the expected result. + */ + private static Stream provideTestCases() { + return Stream.of(Arguments.of(13, 2, 0), // binary: 1101, 2nd bit is 0 + Arguments.of(13, 3, 1), // binary: 1101, 3rd bit is 1 + Arguments.of(4, 2, 0), // binary: 100, 2nd bit is 0 + Arguments.of(4, 3, 1), // binary: 100, 3rd bit is 1 + Arguments.of(1, 1, 1) // binary: 1, 1st bit is 1 + ); + } +}