Merge pull request #38 from Debashis08/feature-graph-implementation

Feature graph implementation

Author: Debashis08

Headers/0003_Graph/0012_DifferenceConstraintsShortestPaths.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include<map>
+#include<string>
+#include<vector>
+using namespace std;
+
+namespace DifferenceConstraintsShortestPaths
+{
+	class Node
+	{
+	public:
+		string data;
+		int distance;
+		Node(string data);
+	};
+
+	class Edge
+	{
+	public:
+		Node* nodeU;
+		Node* nodeV;
+		int weight;
+		Edge(Node* nodeU, Node* nodeV, int weight);
+	};
+
+	class Graph
+	{
+	private:
+		map<Node*, vector<Node*>> _adjlist;
+		map<string, Node*> _nodeMap;
+		vector<Edge*> _edgeList;
+		Node* MakeOrFindNode(string data);
+		void PushDirectedEdge(string valueU, string valueV, int weight);
+		void InitializeSingleSource(Node* sourceNode);
+		void Relax(Edge* edge);
+
+	public:
+		void PushAllDirectedEdges(vector<vector<int>> vectorA, vector<string> vectorX, vector<int> vectorB);
+		bool FindDifferenceConstraintsSolutionBellmanFord();
+		vector<pair<string, int>> GetDifferenceConstrtaintsSolution();
+	};
+}

SourceCodes/0003_Graph/0012_DifferenceConstraintsShortestPaths.cc

@@ -0,0 +1,133 @@
+#include"../Headers/0003_Graph/0012_DifferenceConstraintsShortestPaths.h"
+#include<climits>
+using namespace std;
+
+namespace DifferenceConstraintsShortestPaths
+{
+	Node::Node(string data)
+	{
+		this->data = data;
+		this->distance = INT_MAX;
+	}
+
+	Edge::Edge(Node* nodeU, Node* nodeV, int weight)
+	{
+		this->nodeU = nodeU;
+		this->nodeV = nodeV;
+		this->weight = weight;
+	}
+
+	// Graph Private Member Methods
+	Node* Graph::MakeOrFindNode(string 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;
+	}
+
+	void Graph::PushDirectedEdge(string dataU, string dataV, int weight)
+	{
+		Node* nodeU = this->MakeOrFindNode(dataU);
+		Node* nodeV = this->MakeOrFindNode(dataV);
+
+		this->_adjlist[nodeU].push_back(nodeV);
+		this->_edgeList.push_back(new Edge(nodeU, nodeV, weight));
+	}
+
+	void Graph::InitializeSingleSource(Node* sourceNode)
+	{
+		for (auto& iterator : this->_nodeMap)
+		{
+			iterator.second->distance = INT_MAX;
+		}
+		sourceNode->distance = 0;
+	}
+
+	void Graph::Relax(Edge* edge)
+	{
+		if (edge->nodeU->distance != INT_MAX && (edge->nodeV->distance > (edge->nodeU->distance + edge->weight)))
+		{
+			edge->nodeV->distance = edge->nodeU->distance + edge->weight;
+		}
+	}
+
+	// Graph Public Member Methods
+	void Graph::PushAllDirectedEdges(vector<vector<int>> vectorA, vector<string> vectorX, vector<int> vectorB)
+	{
+		// Creating the Actual Graph
+		string valueU = "";
+		string valueV = "";
+		int weight = 0;
+		for (int i = 0; i < vectorA.size(); i++)
+		{
+			for (int j = 0; j < vectorX.size(); j++)
+			{
+				if (vectorA[i][j] == 1)
+				{
+					valueV= vectorX[j];
+				}
+				if (vectorA[i][j] == -1)
+				{
+					valueU = vectorX[j];
+				}
+			}
+			weight = vectorB[i];
+			this->PushDirectedEdge(valueU, valueV, weight);
+		}
+
+		// Creating all the edges from the additional vertex
+		valueU = "";
+		valueV = "";
+		weight = 0;
+		for (int i = 0; i < vectorX.size(); i++)
+		{
+			valueV = vectorX[i];
+			this->PushDirectedEdge(valueU, valueV, weight);
+		}
+	}
+
+	bool Graph::FindDifferenceConstraintsSolutionBellmanFord()
+	{
+		Node* source = this->_nodeMap[""];
+
+		this->InitializeSingleSource(source);
+
+		for (int i = 0; i < this->_nodeMap.size(); i++)
+		{
+			for (auto& edge : this->_edgeList)
+			{
+				this->Relax(edge);
+			}
+		}
+
+		for (auto& edge : this->_edgeList)
+		{
+			if (edge->nodeV->distance > (edge->nodeU->distance + edge->weight))
+			{
+				return false;
+			}
+		}
+		return true;
+	}
+
+	vector<pair<string, int>> Graph::GetDifferenceConstrtaintsSolution()
+	{
+		vector<pair<string, int>> result;
+		for (auto& node : this->_nodeMap)
+		{
+			if (node.second->data != "")
+			{
+				result.push_back({ node.second->data, node.second->distance });
+			}
+		}
+		return result;
+	}
+}

SourceCodes/0003_Graph/CMakeLists.txt

@@ -11,6 +11,7 @@ set(0003GRAPH_SOURCES
     0009_SingleSourceShortestPathBellmanFord.cc
     0010_DirectedAcyclicGraphShortestPath.cc
     0011_SingleSourceShortestPathDijkstra.cc
+    0012_DifferenceConstraintsShortestPaths.cc
 
 )
 

Tests/0000_CommonUtilities/UnitTestHelper.h

@@ -73,7 +73,6 @@ 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.
@@ -109,7 +108,7 @@ class UnitTestHelper
 	}
 
 	template<typename T>
-	bool NormalizeCyclesAnCompare(vector<T> data1, vector<T> data2)
+	bool NormalizeCyclesAndCompare(vector<T> data1, vector<T> data2)
 	{
 		if (data1.size() != data2.size())
 		{
@@ -158,4 +157,27 @@ class UnitTestHelper
 			});
 		return data;
 	}
+
+	template<typename T1, typename T2>
+	string SortVectorOfPairAndSerialize(vector<pair<T1, T2>> data)
+	{
+		// Sorting the vector in non-decreasing order on typename T1
+		sort(data.begin(), data.end(), [](const pair<T1, T2>& pair1, const pair<T1, T2>& pair2)
+			{
+				return pair1.first < pair2.first;
+			});
+
+		// Serializing the vector to string
+		string result = "";
+		for (auto& iterator : data)
+		{
+			result += iterator.first + "(" + to_string(iterator.second) + ")" + " ";
+		}
+
+		if (!result.empty())
+		{
+			result.pop_back();
+		}
+		return result;
+	}
 };

Tests/0003_Graph/0005_HamiltonianPathAndCycleTest.cc

@@ -28,6 +28,6 @@ namespace HamiltonianPathAndCycle
 
 		ASSERT_TRUE(isHamiltonianCyclePresent);
 		ASSERT_TRUE(isHamiltonianPathPresent);
-		ASSERT_TRUE(unitTestHelper.NormalizeCyclesAnCompare(hamiltonianPathActualResult, hamiltonianPathExpectedResult));
+		ASSERT_TRUE(unitTestHelper.NormalizeCyclesAndCompare(hamiltonianPathActualResult, hamiltonianPathExpectedResult));
 	}
 }

Tests/0003_Graph/0012_DifferenceConstraintsShortestPathsTest.cc

@@ -0,0 +1,40 @@
+#include<gtest/gtest.h>
+#include"../Headers/0003_Graph/0012_DifferenceConstraintsShortestPaths.h"
+#include"../0000_CommonUtilities/UnitTestHelper.h"
+using namespace std;
+
+namespace DifferenceConstraintsShortestPaths
+{
+	UnitTestHelper unitTestHelper;
+
+	TEST(DifferenceConstraints, SimpleGraph)
+	{
+		Graph graph;
+
+		vector<vector<int>> vectorA = 
+		{
+			{1, -1, 0, 0, 0},
+			{1, 0, 0, 0, -1},
+			{0, 1, 0, 0, -1},
+			{-1, 0, 1, 0, 0},
+			{-1, 0, 0, 1, 0},
+			{0, 0, -1, 1, 0},
+			{0, 0, -1, 0, 1},
+			{0, 0, 0, -1, 1},
+		};
+		vector<string> vectorX = { "v1", "v2", "v3", "v4", "v5" };
+		vector<int> vectorB = {0, -1, 1, 5, 4, -1, -3, -3};
+		vector<pair<string, int>> expectedSolution =
+		{
+			{"v2", -3},
+			{"v5", -4},
+			{"v1", -5},
+			{"v4", -1},
+			{"v3", 0},
+		};
+		graph.PushAllDirectedEdges(vectorA, vectorX, vectorB);
+
+		ASSERT_TRUE(graph.FindDifferenceConstraintsSolutionBellmanFord());
+		ASSERT_EQ(unitTestHelper.SortVectorOfPairAndSerialize(graph.GetDifferenceConstrtaintsSolution()), unitTestHelper.SortVectorOfPairAndSerialize(expectedSolution));
+	}
+}

Tests/0003_Graph/CMakeLists.txt

@@ -23,6 +23,7 @@ add_executable(
   0009_SingleSourceShortestPathBellmanFordTest.cc
   0010_DirectedAcyclicGraphShortestPathTest.cc
   0011_SingleSourceShortestPathDijkstraTest.cc
+  0012_DifferenceConstraintsShortestPathsTest.cc
 )
 
 target_link_libraries(