Merge pull request #21 from Debashis08/feature-graph-implementation

topological sort and test implemented

Author: Debashis08

Headers/0003_Graph/0003_TopologicalSort.h

@@ -22,13 +22,15 @@ class TopologicalSortGraph
 {
 private:
     int time;
+    bool hasCycle;
     map<TopologicalSortNode*, list<TopologicalSortNode*>> _adjlist;
     map<int, TopologicalSortNode*> _nodeMap;
     TopologicalSortNode* MakeOrFindNode(int value);
     list<TopologicalSortNode*> _topologicalSortedNodeList;
     void DepthFirstSearch(TopologicalSortNode* DFSNode);
 public:
     void PushDirectedEdge(int valueU, int valueV);
+    void PushSingleNode(int valueU);
     void TopologicalSort();
     vector<pair<int, pair<int, int>>> ShowTopologicalSortResult();
 };

SourceCodes/0003_Graph/0003_TopologicalSort.cc

@@ -2,6 +2,7 @@
 #include<vector>
 #include<utility>
 #include<climits>
+#include<stdexcept>
 using namespace std;
 
 TopologicalSortNode::TopologicalSortNode(int value)
@@ -40,6 +41,11 @@ void TopologicalSortGraph::DepthFirstSearch(TopologicalSortNode* nodeU)
 			nodeV->parent = nodeU;
 			this->DepthFirstSearch(nodeV);
 		}
+		else if (nodeV->color == GRAY)
+		{
+			this->hasCycle = true;
+			return;
+		}
 	}
 	nodeU->color = BLACK;
 	this->time++;
@@ -55,6 +61,11 @@ void TopologicalSortGraph::PushDirectedEdge(int valueU, int valueV)
 	this->_adjlist[nodeU].push_back(nodeV);
 }
 
+void TopologicalSortGraph::PushSingleNode(int valueU)
+{
+	TopologicalSortNode* nodeU = this->MakeOrFindNode(valueU);
+}
+
 void TopologicalSortGraph::TopologicalSort()
 {
 	this->time = 0;
@@ -63,12 +74,20 @@ void TopologicalSortGraph::TopologicalSort()
 		if (iterator.second->color == WHITE)
 		{
 			this->DepthFirstSearch(iterator.second);
+			if (this->hasCycle == true)
+			{
+				break;
+			}
 		}
 	}
 }
 
 vector<pair<int, pair<int, int>>> TopologicalSortGraph::ShowTopologicalSortResult()
 {
+	if (this->hasCycle == true)
+	{
+		throw runtime_error("Cycle Detected");
+	}
 	vector<pair<int, pair<int, int>>> result;
 	for (auto& node : this->_topologicalSortedNodeList)
 	{

Tests/0003_Graph/0003_TopologicalSortTest.cc

@@ -0,0 +1,107 @@
+#include<gtest/gtest.h>
+#include "../Headers/0003_Graph/0003_TopologicalSort.h"
+#include "../0000_CommonUtilities/UnitTestHelper.h"
+
+namespace TopologicalSortTest
+{
+	UnitTestHelper unitTestHelper;
+
+	TEST(TopoSortTesting, ShowTopoSortResult)
+	{
+		TopologicalSortGraph graph;
+
+        graph.PushDirectedEdge(1, 2);
+        graph.PushDirectedEdge(1, 4);
+        graph.PushDirectedEdge(2, 3);
+        graph.PushDirectedEdge(4, 3);
+        graph.PushSingleNode(5);
+        graph.PushDirectedEdge(6, 7);
+        graph.PushDirectedEdge(6, 8);
+        graph.PushDirectedEdge(7, 4);
+        graph.PushDirectedEdge(7, 8);
+        graph.PushDirectedEdge(9, 8);
+
+        graph.TopologicalSort();
+
+        string actualResult = unitTestHelper.VerifyVectorResult(graph.ShowTopologicalSortResult());
+        string expectedResult = "9(17,18) 6(11,16) 7(12,15) 8(13,14) 5(9,10) 1(1,8) 4(6,7) 2(2,5) 3(3,4)";
+
+        EXPECT_EQ(actualResult, expectedResult);
+	}
+
+    // Test with a larger graph and multiple paths between nodes
+    TEST(TopoSortTesting, LargeGraphMultiplePaths)
+    {
+        TopologicalSortGraph graph;
+        graph.PushDirectedEdge(1, 2);
+        graph.PushDirectedEdge(1, 3);
+        graph.PushDirectedEdge(2, 4);
+        graph.PushDirectedEdge(3, 4);
+        graph.PushDirectedEdge(4, 5);
+        graph.PushDirectedEdge(5, 6);
+        graph.PushDirectedEdge(6, 7);
+
+        graph.TopologicalSort();
+        string actualResult = unitTestHelper.VerifyVectorResult(graph.ShowTopologicalSortResult());
+        string expectedResult = "1(1,14) 3(12,13) 2(2,11) 4(3,10) 5(4,9) 6(5,8) 7(6,7)";
+
+        EXPECT_EQ(actualResult, expectedResult);
+    }
+
+    // Test with a graph containing disconnected components
+    TEST(TopoSortTesting, DisconnectedGraph)
+    {
+        TopologicalSortGraph graph;
+        graph.PushDirectedEdge(1, 2);
+        graph.PushDirectedEdge(3, 4);
+        graph.PushDirectedEdge(5, 6);
+
+        graph.TopologicalSort();
+        string actualResult = unitTestHelper.VerifyVectorResult(graph.ShowTopologicalSortResult());
+        string expectedResult = "5(9,12) 6(10,11) 3(5,8) 4(6,7) 1(1,4) 2(2,3)";
+
+        EXPECT_EQ(actualResult, expectedResult);
+    }
+
+    // Test with a graph that has multiple nodes pointing to the same node
+    TEST(TopoSortTesting, MultipleIncomingEdges)
+    {
+        TopologicalSortGraph graph;
+        graph.PushDirectedEdge(1, 3);
+        graph.PushDirectedEdge(2, 3);
+        graph.PushDirectedEdge(3, 4);
+
+        graph.TopologicalSort();
+        string actualResult = unitTestHelper.VerifyVectorResult(graph.ShowTopologicalSortResult());
+        string expectedResult = "2(7,8) 1(1,6) 3(2,5) 4(3,4)";
+
+        EXPECT_EQ(actualResult, expectedResult);
+    }
+
+    // Test for a single-node graph to check the base case
+    TEST(TopoSortTesting, SingleNodeGraph)
+    {
+        TopologicalSortGraph graph;
+        graph.PushSingleNode(1);
+
+        graph.TopologicalSort();
+        string actualResult = unitTestHelper.VerifyVectorResult(graph.ShowTopologicalSortResult());
+        string expectedResult = "1(1,2)";
+
+        EXPECT_EQ(actualResult, expectedResult);
+    }
+
+    // Test with a cyclic graph to verify it can detect cycles (assuming cycle detection is implemented)
+    TEST(TopoSortTesting, CyclicGraph)
+    {
+        TopologicalSortGraph graph;
+        graph.PushDirectedEdge(1, 2);
+        graph.PushDirectedEdge(2, 3);
+        graph.PushDirectedEdge(3, 1);  // Cycle: 1 -> 2 -> 3 -> 1
+
+        graph.TopologicalSort();
+         
+        // Expected output if cycle detection is implemented
+        EXPECT_THROW(graph.ShowTopologicalSortResult(), runtime_error);
+    }
+}