Enhance docs, add more tests in SingleBitOperations (#5860)

Author: Hardvan

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

@@ -1,34 +1,68 @@
 package com.thealgorithms.bitmanipulation;
 
-/*
+/**
+ * A utility class for performing single-bit operations on integers.
+ * These operations include flipping, setting, clearing, and getting
+ * individual bits at specified positions.
+ *
+ * Bit positions are zero-indexed (i.e., the least significant bit is at position 0).
+ * These methods leverage bitwise operations for optimal performance.
+ *
+ * Examples:
+ * - `flipBit(3, 1)` flips the bit at index 1 in binary `11` (result: `1`).
+ * - `setBit(4, 0)` sets the bit at index 0 in `100` (result: `101` or 5).
+ * - `clearBit(7, 1)` clears the bit at index 1 in `111` (result: `101` or 5).
+ * - `getBit(6, 0)` checks if the least significant bit is set (result: `0`).
+ *
+ * Time Complexity: O(1) for all operations.
+ *
  * Author: lukasb1b (https://github.com/lukasb1b)
  */
-
 public final class SingleBitOperations {
     private SingleBitOperations() {
     }
+
     /**
-     * Flip the bit at position 'bit' in 'num'
+     * Flips (toggles) the bit at the specified position.
+     *
+     * @param num the input number
+     * @param bit the position of the bit to flip (0-indexed)
+     * @return the new number after flipping the specified bit
      */
     public static int flipBit(final int num, final int bit) {
         return num ^ (1 << bit);
     }
+
     /**
-     * Set the bit at position 'bit' to 1 in the 'num' variable
+     * Sets the bit at the specified position to 1.
+     *
+     * @param num the input number
+     * @param bit the position of the bit to set (0-indexed)
+     * @return the new number after setting the specified bit to 1
      */
     public static int setBit(final int num, final int bit) {
         return num | (1 << bit);
     }
+
     /**
-     * Clears the bit located at 'bit' from 'num'
+     * Clears the bit at the specified position (sets it to 0).
+     *
+     * @param num the input number
+     * @param bit the position of the bit to clear (0-indexed)
+     * @return the new number after clearing the specified bit
      */
     public static int clearBit(final int num, final int bit) {
         return num & ~(1 << bit);
     }
+
     /**
-     * Get the bit located at 'bit' from 'num'
+     * Gets the bit value (0 or 1) at the specified position.
+     *
+     * @param num the input number
+     * @param bit the position of the bit to retrieve (0-indexed)
+     * @return 1 if the bit is set, 0 otherwise
      */
     public static int getBit(final int num, final int bit) {
-        return ((num >> bit) & 1);
+        return (num >> bit) & 1;
     }
 }

src/test/java/com/thealgorithms/bitmanipulation/SingleBitOperationsTest.java

@@ -2,35 +2,60 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-import org.junit.jupiter.api.Test;
+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 class SingleBitOperationsTest {
+class SingleBitOperationsTest {
 
-    @Test
-    public void flipBitTest() {
-        assertEquals(1, SingleBitOperations.flipBit(3, 1));
-        assertEquals(11, SingleBitOperations.flipBit(3, 3));
+    @ParameterizedTest
+    @MethodSource("provideFlipBitTestCases")
+    void testFlipBit(int input, int bit, int expected) {
+        assertEquals(expected, SingleBitOperations.flipBit(input, bit));
     }
 
-    @Test
-    public void setBitTest() {
-        assertEquals(5, SingleBitOperations.setBit(4, 0));
-        assertEquals(4, SingleBitOperations.setBit(4, 2));
-        assertEquals(5, SingleBitOperations.setBit(5, 0));
-        assertEquals(14, SingleBitOperations.setBit(10, 2));
-        assertEquals(15, SingleBitOperations.setBit(15, 3));
-        assertEquals(2, SingleBitOperations.setBit(0, 1));
+    private static Stream<Arguments> provideFlipBitTestCases() {
+        return Stream.of(Arguments.of(3, 1, 1), // Binary: 11 -> 01
+            Arguments.of(3, 3, 11) // Binary: 11 -> 1011
+        );
     }
 
-    @Test
-    public void clearBitTest() {
-        assertEquals(5, SingleBitOperations.clearBit(7, 1));
-        assertEquals(5, SingleBitOperations.clearBit(5, 1));
+    @ParameterizedTest
+    @MethodSource("provideSetBitTestCases")
+    void testSetBit(int input, int bit, int expected) {
+        assertEquals(expected, SingleBitOperations.setBit(input, bit));
     }
 
-    @Test
-    public void getBitTest() {
-        assertEquals(0, SingleBitOperations.getBit(6, 0));
-        assertEquals(1, SingleBitOperations.getBit(7, 1));
+    private static Stream<Arguments> provideSetBitTestCases() {
+        return Stream.of(Arguments.of(4, 0, 5), // 100 -> 101
+            Arguments.of(4, 2, 4), // 100 -> 100 (bit already set)
+            Arguments.of(0, 1, 2), // 00 -> 10
+            Arguments.of(10, 2, 14) // 1010 -> 1110
+        );
+    }
+
+    @ParameterizedTest
+    @MethodSource("provideClearBitTestCases")
+    void testClearBit(int input, int bit, int expected) {
+        assertEquals(expected, SingleBitOperations.clearBit(input, bit));
+    }
+
+    private static Stream<Arguments> provideClearBitTestCases() {
+        return Stream.of(Arguments.of(7, 1, 5), // 111 -> 101
+            Arguments.of(5, 1, 5) // 101 -> 101 (bit already cleared)
+        );
+    }
+
+    @ParameterizedTest
+    @MethodSource("provideGetBitTestCases")
+    void testGetBit(int input, int bit, int expected) {
+        assertEquals(expected, SingleBitOperations.getBit(input, bit));
+    }
+
+    private static Stream<Arguments> provideGetBitTestCases() {
+        return Stream.of(Arguments.of(6, 0, 0), // 110 -> Bit 0: 0
+            Arguments.of(7, 1, 1) // 111 -> Bit 1: 1
+        );
     }
 }