test: added tests for scc

Tests/0000_CommonUtilities/UnitTestHelper.h

@@ -3,6 +3,7 @@
 #include<iostream>
 #include<vector>
 #include<string>
+#include<algorithm>
 using namespace std;
 
 class UnitTestHelper
@@ -71,4 +72,39 @@ class UnitTestHelper
 		}
 		return result;
 	}
+
+
+	// This helper method is used to sort the vector of vectors of a particular typename.
+	// Each inner vector is sorted first.
+	// Then each of them are sorted by their first element, in increasing order.
+	template<typename T>
+	vector<vector<T>> SortVectorOfVectors(vector<vector<T>> data)
+	{
+		// Step 1: Sorting each inner vectors.
+		for (auto& innerVector : data)
+		{
+			sort(innerVector.begin(), innerVector.end());
+		}
+
+		// Step 2: Sorting all the vectors by their first element, in increasing order.
+		sort(data.begin(), data.end(), [](const vector<T>& a, const vector<T>& b)
+			{
+				// Checking if both inner vectors are empty to prevent out-of-bounds access.
+				if (a.empty() && b.empty())
+					return false;
+
+				// Considering empty vector as less than non-empty vector.
+				if (a.empty())
+					return true;
+
+				// Considering non-empty vector as greater than empty vector.
+				if (b.empty())
+					return false;
+
+				// Comparing the first elements of each vector.
+				return (a[0] < b[0]);
+			});
+
+		return data;
+	}
 };

Tests/0003_Graph/0004_StronglyConnectedComponentsTest.cc

@@ -6,6 +6,7 @@ namespace StronglyConnectedComponentsTest
 {
 	UnitTestHelper  unitTestHelper;
 
+    // Test case: Testing with a simple graph.
 	TEST(StronglyConnectedComponentsTesting, SimpleGraphTest)
 	{
 		StronglyConnectedComponentsGraph graph;
@@ -25,8 +26,77 @@ namespace StronglyConnectedComponentsTest
 		graph.PushDirectedEdge(7, 8);
 		graph.PushDirectedEdge(8, 6);
 
-		string actualResult = unitTestHelper.VerifyVectorResult(graph.FindAllStronglyConnectedComponents());
-		string expectedResult = "[6 8 7][1 5][2 3][4]";
-		EXPECT_EQ(actualResult, expectedResult);
+        auto actualResult = graph.FindAllStronglyConnectedComponents();
+        vector<vector<int>> expectedResult = { {6, 8, 7},{1, 5},{2, 3},{4} };
+        EXPECT_EQ(unitTestHelper.SortVectorOfVectors(actualResult), unitTestHelper.SortVectorOfVectors(expectedResult));
 	}
+
+    // Test case: Single Node.
+    TEST(StronglyConnectedComponentsTesting, SingleNodeTest) 
+    {
+        StronglyConnectedComponentsGraph graph;
+        graph.PushSingleNode(1);
+
+        auto actualResult = graph.FindAllStronglyConnectedComponents();
+        vector<vector<int>> expectedResult = { {1} };
+        EXPECT_EQ(unitTestHelper.SortVectorOfVectors(actualResult), unitTestHelper.SortVectorOfVectors(expectedResult));
+    }
+
+    // Test case: Disconnected Graph.
+    TEST(StronglyConnectedComponentsTesting, DisconnectedGraphTest)
+    {
+        StronglyConnectedComponentsGraph graph;
+        graph.PushSingleNode(1);
+        graph.PushSingleNode(2);
+        graph.PushSingleNode(3);
+
+        auto actualResult = graph.FindAllStronglyConnectedComponents();
+        vector<vector<int>> expectedResult = { {1},{3},{2} };
+        EXPECT_EQ(unitTestHelper.SortVectorOfVectors(actualResult), unitTestHelper.SortVectorOfVectors(expectedResult));
+    }
+
+    // Test case: Chain of Nodes.
+    TEST(StronglyConnectedComponentsTesting, ChainOfNodesTest)
+    {
+        StronglyConnectedComponentsGraph graph;
+        graph.PushDirectedEdge(1, 2);
+        graph.PushDirectedEdge(2, 3);
+        graph.PushDirectedEdge(3, 4);
+
+        auto actualResult = graph.FindAllStronglyConnectedComponents();
+        vector<vector<int>> expectedResult = { {2},{1},{3},{4} };
+        EXPECT_EQ(unitTestHelper.SortVectorOfVectors(actualResult), unitTestHelper.SortVectorOfVectors(expectedResult));
+    }
+
+    // Test case: Bidirectional Edge.
+    TEST(StronglyConnectedComponentsTesting, BidirectionalEdgeTest)
+    {
+        StronglyConnectedComponentsGraph graph;
+        graph.PushDirectedEdge(1, 2);
+        graph.PushDirectedEdge(2, 1);
+
+        auto actualResult = graph.FindAllStronglyConnectedComponents();
+        vector<vector<int>> expectedResult = { {2, 1} };
+        EXPECT_EQ(unitTestHelper.SortVectorOfVectors(actualResult), unitTestHelper.SortVectorOfVectors(expectedResult));
+    }
+
+    // Test case: Complex Graph.
+    TEST(StronglyConnectedComponentsTesting, ComplexGraphTest)
+    {
+        StronglyConnectedComponentsGraph graph;
+
+        // Graph structure with multiple SCCs and isolated nodes.
+        graph.PushDirectedEdge(1, 2);
+        graph.PushDirectedEdge(2, 3);
+        graph.PushDirectedEdge(3, 1);  // Cycle: 1 -> 2 -> 3 -> 1
+        graph.PushDirectedEdge(4, 5);
+        graph.PushDirectedEdge(5, 6);
+        graph.PushDirectedEdge(6, 4);  // Cycle: 4 -> 5 -> 6 -> 4
+        graph.PushDirectedEdge(7, 8);  // Single direction: 7 -> 8
+        graph.PushSingleNode(9);       // Isolated node.
+
+        auto actualResult = graph.FindAllStronglyConnectedComponents();
+        vector<vector<int>> expectedResult = { {4, 6, 5},{7}, { 2, 3, 1},{8}, {9} };
+        EXPECT_EQ(unitTestHelper.SortVectorOfVectors(actualResult), unitTestHelper.SortVectorOfVectors(expectedResult));
+    }
 }