LowestSetBit implementation and tests added

Author: prayas7102

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

@@ -0,0 +1,18 @@
+package com.thealgorithms.bitmanipulation;
+
+public class LowestSetBit {
+
+    /**
+     * Isolates the lowest set bit of the given number.
+     * For example, if n = 18 (binary: 10010), the result will be 2 (binary: 00010).
+     *
+     * @param n the number whose lowest set bit will be isolated
+     * @return the isolated lowest set bit of n
+     */
+    public static int isolateLowestSetBit(int n) {
+        // Isolate the lowest set bit using n & -n
+        return n & -n;
+    }
+
+}
+

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

@@ -0,0 +1,49 @@
+package com.thealgorithms.bitmanipulation;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class LowestSetBitTest {
+    @Test
+    void testLowestSetBitWithPositiveNumber() {
+        // Test with a general positive number
+        assertEquals(2, LowestSetBit.isolateLowestSetBit(18)); // 18 in binary: 10010, lowest bit is 2
+    }
+
+    @Test
+    void testLowestSetBitWithZero() {
+        // Test with zero (edge case, no set bits)
+        assertEquals(0, LowestSetBit.isolateLowestSetBit(0)); // 0 has no set bits, result should be 0
+    }
+
+    @Test
+    void testLowestSetBitWithOne() {
+        // Test with number 1 (lowest set bit is 1 itself)
+        assertEquals(1, LowestSetBit.isolateLowestSetBit(1)); // 1 in binary: 0001, lowest bit is 1
+    }
+
+    @Test
+    void testLowestSetBitWithPowerOfTwo() {
+        // Test with a power of two (only one set bit)
+        assertEquals(16, LowestSetBit.isolateLowestSetBit(16)); // 16 in binary: 10000, lowest bit is 16
+    }
+
+    @Test
+    void testLowestSetBitWithAllBitsSet() {
+        // Test with a number with multiple set bits (like 7)
+        assertEquals(1, LowestSetBit.isolateLowestSetBit(7)); // 7 in binary: 111, lowest bit is 1
+    }
+
+    @Test
+    void testLowestSetBitWithNegativeNumber() {
+        // Test with a negative number (-1 in two's complement has all bits set)
+        assertEquals(1, LowestSetBit.isolateLowestSetBit(-1)); // -1 in two's complement is all 1s, lowest bit is 1
+    }
+
+    @Test
+    void testLowestSetBitWithLargeNumber() {
+        // Test with a large number
+        assertEquals(64, LowestSetBit.isolateLowestSetBit(448)); // 448 in binary: 111000000, lowest bit is 64
+    }
+}