Enhance docs, add more tests in ReverseBits (#5859)

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

@@ -1,14 +1,33 @@
 package com.thealgorithms.bitmanipulation;
 
 /**
- * Converts any Octal Number to a Binary Number
+ * This class provides a method to reverse the bits of a 32-bit integer.
+ * Reversing the bits means that the least significant bit (LSB) becomes
+ * the most significant bit (MSB) and vice versa.
+ *
+ * Example:
+ * Input (binary): 00000010100101000001111010011100 (43261596)
+ * Output (binary): 00111001011110000010100101000000 (964176192)
+ *
+ * Time Complexity: O(32) - A fixed number of 32 iterations
+ * Space Complexity: O(1) - No extra space used
+ *
+ * Note:
+ * - If the input is negative, Java handles it using two’s complement representation.
+ * - This function works on 32-bit integers by default.
+ *
  * @author Bama Charan Chhandogi
  */
-
 public final class ReverseBits {
     private ReverseBits() {
     }
 
+    /**
+     * Reverses the bits of a 32-bit integer.
+     *
+     * @param n the integer whose bits are to be reversed
+     * @return the integer obtained by reversing the bits of the input
+     */
     public static int reverseBits(int n) {
         int result = 0;
         int bitCount = 32;

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

@@ -2,14 +2,40 @@
 
 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;
 
 class ReverseBitsTest {
 
-    @Test
-    void testReverseBits() {
-        assertEquals(0, ReverseBits.reverseBits(0));
-        assertEquals(-1, ReverseBits.reverseBits(-1));
-        assertEquals(964176192, ReverseBits.reverseBits(43261596));
+    @ParameterizedTest
+    @MethodSource("provideTestCases")
+    void testReverseBits(int input, int expected) {
+        assertEquals(expected, ReverseBits.reverseBits(input));
+    }
+
+    private static Stream<Arguments> provideTestCases() {
+        return Stream.of(
+            // Edge case: All bits are 0
+            Arguments.of(0, 0),
+
+            // Edge case: All bits are 1 (Two’s complement representation of -1)
+            Arguments.of(-1, -1),
+
+            // Case with random number 43261596
+            Arguments.of(43261596, 964176192),
+
+            // Case with maximum positive value for 32-bit integer
+            Arguments.of(Integer.MAX_VALUE, -2),
+
+            // Case with minimum value (all bits 1 except the sign bit)
+            Arguments.of(Integer.MIN_VALUE, 1),
+
+            // Case with a single bit set (2^0 = 1)
+            Arguments.of(1, Integer.MIN_VALUE),
+
+            // Case with alternating bits: 0b101010...10 (in binary)
+            Arguments.of(0xAAAAAAAA, 0x55555555));
     }
 }