Add Topological Sort using DFS with unit tests

Author: Mansi5164

src/main/java/com/thealgorithms/dynamicprogramming/KadanesAlgorithmTest.java

@@ -0,0 +1,24 @@
+package com.thealgorithms.dynamicprogramming;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class KadanesAlgorithmTest {
+    @Test
+    public void testPositiveNumbers() {
+        int[] arr = {1, 2, 3, 4};
+        Assertions.assertEquals(10, KadanesAlgorithm.maxSubArraySum(arr));
+    }
+
+    @Test
+    public void testNegativeNumbers() {
+        int[] arr = {-1, -2, -3, -4};
+        Assertions.assertEquals(-1, KadanesAlgorithm.maxSubArraySum(arr));
+    }
+
+    @Test
+    public void testMixedNumbers() {
+        int[] arr = {-2, 1, -3, 4, -1, 2, 1, -5, 4};
+        Assertions.assertEquals(6, KadanesAlgorithm.maxSubArraySum(arr)); // [4, -1, 2, 1]
+    }
+}