Merge pull request #33 from Debashis08/feature-graph-implementation

Feature graph implementation

Author: Debashis08

Headers/0003_Graph/0008_MinimumSpanningTreePrimAlgorithm.h

@@ -0,0 +1,42 @@
+# pragma once
+
+#include<map>
+#include<vector>
+#include<set>
+using namespace std;
+
+namespace MinimumSpanningTreePrimAlgorithm
+{
+	class Node
+	{
+	public:
+		int data;
+		Node* parent;
+		int key;
+		bool isInOperationalSet;
+		Node(int data);
+	};
+
+	class CompareNodeKey
+	{
+	public:
+		bool operator()(const Node* nodeU, const Node* nodeV) const
+		{
+			return nodeU->key < nodeV->key;
+		}
+	};
+
+	class Graph
+	{
+	private:
+		map<Node*, vector<pair<Node*, int>>> _adjlist;
+		map<int, Node*> _nodeMap;
+		vector<pair<pair<int, int>, int>> _minimumSpanningTree;
+		multiset<Node*, CompareNodeKey> _operationalSet;
+		Node* MakeOrFindNode(int data);
+	public:
+		void PushUndirectedEdge(int valueU, int valueV, int weight);
+		void FindMinimumSpanningTreePrimAlgorithm();
+		vector<pair<pair<int, int>, int>> GetMinimumSpanningTree();
+	};
+}

SourceCodes/0003_Graph/0008_MinimumSpanningTreePrimAlgorithm.cc

@@ -0,0 +1,85 @@
+#include "../Headers/0003_Graph/0008_MinimumSpanningTreePrimAlgorithm.h"
+#include<climits>
+using namespace std;
+
+
+namespace MinimumSpanningTreePrimAlgorithm
+{
+	Node::Node(int data)
+	{
+		this->data = data;
+		this->parent = nullptr;
+		this->key = INT_MAX;
+		this->isInOperationalSet = false;
+	}
+
+	// Graph Private Member Methods
+	Node* Graph::MakeOrFindNode(int data)
+	{
+		Node* node = nullptr;
+		if (this->_nodeMap.find(data) == this->_nodeMap.end())
+		{
+			node = new Node(data);
+			this->_nodeMap[data] = node;
+		}
+		else
+		{
+			node = this->_nodeMap[data];
+		}
+		return node;
+	}
+
+	// Graph Public Member Methods
+	void Graph::PushUndirectedEdge(int dataU, int dataV, int weight)
+	{
+		Node* nodeU = this->MakeOrFindNode(dataU);
+		Node* nodeV = this->MakeOrFindNode(dataV);
+
+		this->_adjlist[nodeU].push_back({nodeV, weight});
+		this->_adjlist[nodeV].push_back({nodeU, weight});
+	}
+
+	void Graph::FindMinimumSpanningTreePrimAlgorithm()
+	{
+		Node* root = this->_nodeMap.begin()->second;
+
+		root->key = 0;
+		for (auto& iterator : this->_nodeMap)
+		{
+			iterator.second->isInOperationalSet = true;
+			this->_operationalSet.insert(iterator.second);
+		}
+
+		while (!this->_operationalSet.empty())
+		{
+			Node* nodeU = *(this->_operationalSet.begin());
+			this->_operationalSet.erase(nodeU);
+			nodeU->isInOperationalSet = false;
+
+			for (auto& iterator : this->_adjlist[nodeU])
+			{
+				Node* nodeV = iterator.first;
+				int weight = iterator.second;
+
+				if (nodeV->isInOperationalSet && weight < nodeV->key)
+				{
+					this->_operationalSet.erase(nodeV);
+					nodeV->key = weight;
+					nodeV->parent = nodeU;
+					this->_operationalSet.insert(nodeV);
+
+				}
+			}
+
+			if (nodeU->parent != nullptr)
+			{
+				this->_minimumSpanningTree.push_back({ {nodeU->parent->data, nodeU->data}, nodeU->key });
+			}
+		}
+	}
+
+	vector<pair<pair<int, int>, int>> Graph::GetMinimumSpanningTree()
+	{
+		return this->_minimumSpanningTree;
+	}
+}

SourceCodes/0003_Graph/CMakeLists.txt

@@ -7,6 +7,7 @@ set(0003GRAPH_SOURCES
     0005_HamiltonianPathAndCycle.cc
     0006_EulerianPathAndCircuit.cc
     0007_MinimumSpanningTreeKruskalAlgorithm.cc
+    0008_MinimumSpanningTreePrimAlgorithm.cc
 
 )
 

Tests/0000_CommonUtilities/UnitTestHelper.h

@@ -150,6 +150,10 @@ class UnitTestHelper
 
 		sort(data.begin(), data.end(), [](const pair<pair<T, T>, T>& pairA, const pair<pair<T, T>, T>& pairB)
 			{
+				if (pairA.second == pairB.second)
+				{
+					return pairA.first.first < pairB.first.first;
+				}
 				return pairA.second < pairB.second;
 			});
 		return data;

Tests/0003_Graph/0008_MinimumSpanningTreePrimAlgorithmTest.cc

@@ -0,0 +1,45 @@
+#include<gtest/gtest.h>
+#include "../Headers/0003_Graph/0008_MinimumSpanningTreePrimAlgorithm.h"
+#include "../0000_CommonUtilities/UnitTestHelper.h"
+
+namespace MinimumSpanningTreePrimAlgorithm
+{
+	UnitTestHelper unitTestHelper;
+
+	TEST(MST, Prim)
+	{
+		Graph graph;
+
+		graph.PushUndirectedEdge(1, 2, 4);
+		graph.PushUndirectedEdge(1, 8, 8);
+		graph.PushUndirectedEdge(2, 8, 11);
+		graph.PushUndirectedEdge(2, 3, 8);
+		graph.PushUndirectedEdge(3, 4, 7);
+		graph.PushUndirectedEdge(3, 9, 2);
+		graph.PushUndirectedEdge(3, 6, 4);
+		graph.PushUndirectedEdge(4, 5, 9);
+		graph.PushUndirectedEdge(4, 6, 14);
+		graph.PushUndirectedEdge(5, 6, 10);
+		graph.PushUndirectedEdge(6, 7, 2);
+		graph.PushUndirectedEdge(7, 8, 1);
+		graph.PushUndirectedEdge(7, 9, 6);
+		graph.PushUndirectedEdge(8, 9, 7);
+
+		graph.FindMinimumSpanningTreePrimAlgorithm();
+
+		vector<pair<pair<int, int>, int>> actualMST = graph.GetMinimumSpanningTree();
+		vector<pair<pair<int, int>, int>> expectedMST =
+		{
+			{{7, 8}, 1},
+			{{3, 9}, 2},
+			{{6, 7}, 2},
+			{{2, 1}, 4},
+			{{3, 6}, 4},
+			{{3, 4}, 7},
+			{{8, 1}, 8},
+			{{4, 5}, 9}
+		};
+
+		ASSERT_EQ(unitTestHelper.SortVectorOfPair(actualMST), unitTestHelper.SortVectorOfPair(expectedMST));
+	}
+}

Tests/0003_Graph/CMakeLists.txt

@@ -19,6 +19,7 @@ add_executable(
   0005_HamiltonianPathAndCycleTest.cc
   0006_EulerianPathAndCircuitTest.cc
   0007_MinimumSpanningTreeKruskalAlgorithmTest.cc
+  0008_MinimumSpanningTreePrimAlgorithmTest.cc
 )
 
 target_link_libraries(