Added loadFromString() method to Graph class.

todo: make it robust to errors in the input string.

Signed-off-by: unknown <saq10002@iteb-219.ad.engr.uconn.edu>

YASI_12/ds.graph.h

@@ -1,6 +1,9 @@
 #pragma once
 #include "common.h"
+#include <sstream>
+#include <string>
 #include "ds.doublylinkedlist.h"
+#include "ds.IntLinearProbingHashTable.h"
 using namespace std;
 
 namespace yasi{
@@ -13,37 +16,169 @@ class EdgeBase;
 template<class V, class Element>
 struct Edge{
 	Element element;
-	V *pStart, *pEnd;
+	float weight;
+	V *start, *end;
+	Edge(V* v1 = NULL, V* v2 = NULL, float w = 0) : start(v1), end(v2), weight(w){}
 };
 
-template<class E>
-typedef DoublyLinkedList< E > EdgeList;
 
 template<class Element, class EdgeElement>
 struct Vertex{
 protected:
 	typedef Vertex<Element, EdgeElement> self;
 	typedef Edge<self, EdgeElement> edge;
 public:	
-	typedef DoublyLinkedList< edge > EdgeList;
+	typedef DoublyLinkedList< edge* > EdgeList;
 	int id;
 	Element element;
 	EdgeList* pInEdges;
 	EdgeList* pOutEdges;
+
+	Vertex(int id = 0) :id(id){
+		pInEdges = new EdgeList;
+		pOutEdges = new EdgeList;
+	}
+
+	virtual ~Vertex(){
+		DELETE_SAFE(pInEdges);
+		DELETE_SAFE(pOutEdges);
+	}
+};
+
+class IGraph{
+public:
+	virtual ~IGraph(){}
+	virtual int numVertices() const = 0;
+	virtual int numEdges() const = 0;
 };
 
 /// Adjacency list data structure
-template<class VertexElement, class EdgeElement>
-class Graph{
+// directed weighted graph
+template<class VertexElement = int, class EdgeElement = char>
+class Graph : public IGraph{
+	/////////////// enable testing /////////////
+	friend class GraphTest;
 public:
 	typedef Vertex<VertexElement, EdgeElement> VertexType;
 	typedef Edge<VertexType, EdgeElement> EdgeType;
 	typedef DoublyLinkedList<VertexType*> VertexList;
 	typedef DoublyLinkedList<EdgeType*> EdgeList;
 protected:
-	VertexList* vertexList;
-	EdgeList*	edgeList;
+	VertexList	vertexList;
+	EdgeList	edgeList;
+	const bool	_weighted;
+
+	void clear(){
+		for (VertexList::iterator i = vertexList.begin(); i != vertexList.end(); i++){
+			DELETE_SAFE(*i);
+		}
+		vertexList.clear();
+		for (EdgeList::iterator i = edgeList.begin(); i != edgeList.end(); i++){
+			DELETE_SAFE(*i);
+		}
+		edgeList.clear();
+	}
+public:
+	Graph(bool weighted = true) :_weighted(weighted){
+	}
+	virtual ~Graph(){
+	}
+	int numVertices() const override{
+		return vertexList.size();
+	}
+	int numEdges() const override{
+		return edgeList.size();
+	}
+	EdgeType* addEdge(VertexType* v1, VertexType* v2, float w = 0){
+		EdgeType* edge = new EdgeType(v1, v2, w);
+		edgeList.pushBack(edge);
+		v1->pOutEdges->pushBack(edge);
+		v2->pInEdges->pushBack(edge);
+		return edge;
+	}
+	VertexType* addVertex(int id){
+		VertexType* pVertex = new VertexType(id);
+		vertexList.pushBack(pVertex);
+		return pVertex;
+	}
+	VertexType* addVertex(int id, VertexElement e){
+		VertexType* pVertex = addVertex(id);
+		pVertex->element = e;
+		return pVertex;
+	}
+
+	// strEdgeList contains non-empty lines
+	// one line for each edge
+	// line format: vid1 vid2 weight
+	void loadFromString(string strEdgeList){
+		clear();
+		stringstream inp(trim(strEdgeList));
+
+		// use a temporary hashtable
+		IntLinearProbingHashTable< VertexType* > ht;
+
+		while (! inp.eof()){
+			int vid1, vid2;
+			float w;
+			// vertices
+			inp >> vid1 >> vid2;
+			// edge weight
+			if (_weighted){
+				inp >> w;
+			}
+			else{
+				w = 0;
+			}
+
+			// create vertices
+			// add them to the graph if not already there
+			VertexType **ppv1, **ppv2;
+			VertexType *pv1, *pv2;
+
+			// first vertex
+			ppv1 = ht.get(vid1);
+			if (!ppv1){
+				pv1 = addVertex(vid1);
+				ht.put(vid1, pv1);
+			}
+			else{
+				pv1 = *ppv1;
+			}
+			// second vertex
+			ppv2 = ht.get(vid2);
+			if (!ppv2){
+				pv2 = addVertex(vid2);
+				ht.put(vid2, pv2);
+			}
+			else{
+				pv2 = *ppv2;
+			}
+			// create edge
+			addEdge(pv1, pv2, w);
+		}
+	}
+}; // class Graph
+
+class GraphTest : public yasi::Test{
+public:
+	void loadFromString(){
+		Graph<int> g;
+
+		// simple triangle
+		string triangle = 
+			"1 2 12\n"
+			"1 3 13\n"
+			"2 3 23\n";
+		g.loadFromString(triangle);
+
+		// test
+		ASSERT_EQ(3, g.numVertices());
+		ASSERT_EQ(3, g.numEdges());
+	}
+
 };
 
-}
-}
+ADD_TEST_F(GraphTest, loadFromString);
+
+} // namespace ds
+} // namespace yasi

YASI_12/main.cpp

@@ -12,6 +12,7 @@
 #include "ds.intlinearprobinghashtable.h"
 #include "ds.linearprobinghashtable.h"
 #include "ds.hopscotchhashtable.h"
+#include "ds.graph.h"
 
 //#include "Sorter.h"
 

YASI_12/utils.h

@@ -1,5 +1,9 @@
 #pragma once
 #include "common.h"
+#include <algorithm> 
+#include <functional> 
+#include <cctype>
+#include <locale>
 #include <string>
 using namespace std;
 
@@ -83,6 +87,29 @@ int whichPowerOfTwo(unsigned int n){
 	}
 }
 
+
+//////////////////////////////////////////
+//// string trimming functions from
+//// http://stackoverflow.com/questions/216823/whats-the-best-way-to-trim-stdstring
+/////////////////////////////////////////
+
+// trim from start
+inline std::string &ltrim(std::string &s) {
+	s.erase(s.begin(), std::find_if(s.begin(), s.end(), std::not1(std::ptr_fun<int, int>(std::isspace))));
+	return s;
+}
+
+// trim from end
+inline std::string &rtrim(std::string &s) {
+	s.erase(std::find_if(s.rbegin(), s.rend(), std::not1(std::ptr_fun<int, int>(std::isspace))).base(), s.end());
+	return s;
+}
+
+// trim from both ends
+inline std::string &trim(std::string &s) {
+	return ltrim(rtrim(s));
+}
+
 ///////////// enable in compile-time a certain code block depending on boolean predicate /////////////
 ///////////// also, check if a certain class contains a certain function ///////////////////////////////
 //////////////////////// see http://stackoverflow.com/questions/257288/is-it-possible-to-write-a-c-template-to-check-for-a-functions-existence#264088

gtest-1.7.0/msvc/gtest/gtest.tlog/gtest.lastbuildstate

@@ -1,2 +1,2 @@
 #TargetFrameworkVersion=v4.0:PlatformToolSet=v120:EnableManagedIncrementalBuild=false:VCToolArchitecture=Native32Bit
-Debug|Win32|D:\DropBox\My Dropbox\Projects\C++\YASI\|
+Debug|Win32|C:\Saad\Dropbox\Projects\C++\YASI\|