Add find non repeating number algorithm (#4328)

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

@@ -0,0 +1,17 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * Find Non Repeating Number
+ * @author Bama Charan Chhandogi (https://github.com/BamaCharanChhandogi)
+ */
+
+public class NonRepeatingNumberFinder {
+
+    public static int findNonRepeatingNumber(int[] arr) {
+        int result = 0;
+        for (int num : arr) {
+            result ^= num;
+        }
+        return result;
+    }
+}

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

@@ -0,0 +1,23 @@
+package com.thealgorithms.bitmanipulation;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test case for Non Repeating Number Finder
+ * @author Bama Charan Chhandogi (https://github.com/BamaCharanChhandogi)
+ */
+
+class NonRepeatingNumberFinderTest {
+
+    @Test
+    void testNonRepeatingNumberFinder() {
+        int arr[] = {1, 2, 1, 2, 6};
+        assertEquals(6, NonRepeatingNumberFinder.findNonRepeatingNumber(arr));
+        int arr1[] = {1, 2, 1, 2};
+        assertEquals(0, NonRepeatingNumberFinder.findNonRepeatingNumber(arr1));
+        int arr2[] = {12};
+        assertEquals(12, NonRepeatingNumberFinder.findNonRepeatingNumber(arr2));
+    }
+}