feat: add ToggleKthBit algorithm with test

Author: Rahul-18r

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

@@ -0,0 +1,30 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * The ToggleKthBit class provides a method to toggle the K-th bit of a given number.
+ * 
+ * Toggling means: if the K-th bit is 1, it becomes 0; if it's 0, it becomes 1.
+ * 
+ * Example:
+ *   Input: n = 10 (1010 in binary), k = 1
+ *   Output: 8  (1000 in binary)
+ * 
+ * @author Rahul 
+ */
+public final class ToggleKthBit {
+
+    private ToggleKthBit() {
+        // Utility class, no need to instantiate
+    }
+
+    /**
+     * Toggles the K-th bit (0-based index from right) of a number.
+     *
+     * @param n the number to toggle the bit in
+     * @param k the position of the bit to toggle (0-based)
+     * @return the number after toggling the K-th bit
+     */
+    public static int toggleKthBit(int n, int k) {
+        return n ^ (1 << k);
+    }
+}

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

@@ -0,0 +1,15 @@
+package com.thealgorithms.bitmanipulation;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+public class ToggleKthBitTest {
+
+    @Test
+    public void testToggleKthBit() {
+        assertEquals(8, ToggleKthBit.toggleKthBit(10, 1));  // 1010 ^ (1<<1) = 1000
+        assertEquals(14, ToggleKthBit.toggleKthBit(10, 2)); // 1010 ^ (1<<2) = 1110
+        assertEquals(2, ToggleKthBit.toggleKthBit(0, 1));   // 0000 ^ (1<<1) = 0010
+        assertEquals(0, ToggleKthBit.toggleKthBit(1, 0));   // 0001 ^ (1<<0) = 0000
+    }
+}