Add NumberAppearingOddTimes algorithm (#5633)

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

@@ -0,0 +1,21 @@
+package com.thealgorithms.bitmanipulation;
+
+/**
+ * Find the Number Appearing Odd Times in an array
+ * @author Lakshyajeet Singh Goyal (https://github.com/DarkMatter-999)
+ */
+
+public final class NumberAppearingOddTimes {
+    private NumberAppearingOddTimes() {
+    }
+    public static int findOddOccurrence(int[] arr) {
+        int result = 0;
+
+        // XOR all elements in the array
+        for (int num : arr) {
+            result ^= num;
+        }
+
+        return result;
+    }
+}

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

@@ -0,0 +1,23 @@
+package com.thealgorithms.bitmanipulation;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class NumberAppearingOddTimesTest {
+
+    @Test
+    void testFindOddOccurrence() {
+        int[] arr1 = {5, 6, 7, 8};
+        assertEquals(12, NumberAppearingOddTimes.findOddOccurrence(arr1));
+
+        int[] arr2 = {2, 3, 5, 4, 5, 2, 4, 3, 5, 2, 4, 4, 2};
+        assertEquals(5, NumberAppearingOddTimes.findOddOccurrence(arr2));
+
+        int[] arr3 = {10, 10, 20, 20, 30};
+        assertEquals(30, NumberAppearingOddTimes.findOddOccurrence(arr3));
+
+        int[] arr4 = {-5, -5, -3, -3, -7, -7, -7};
+        assertEquals(-7, NumberAppearingOddTimes.findOddOccurrence(arr4));
+    }
+}