walktrap02.patch

Only in walktrap: .#communities.cpp
Only in walktrap: .#communities.h
diff -ru walktrap_clean/example.net walktrap/example.net
--- walktrap_clean/example.net	2005-06-08 11:32:42.000000000 +0200
+++ walktrap/example.net	2009-12-03 17:05:35.000000000 +0100
@@ -16,7 +16,7 @@
 3 7
 4 10
 4 1
-5 7 3.2
+5 7
 # the line above mean that there is an edges between 5 and 7 (with weight 3.2)
 
 5 11
diff -ru walktrap_clean/graph.cpp walktrap/graph.cpp
--- walktrap_clean/graph.cpp	2005-06-07 15:20:58.000000000 +0200
+++ walktrap/graph.cpp	2009-12-03 17:02:55.000000000 +0100
@@ -1,308 +1,308 @@
-// File: graph.cpp
-//-----------------------------------------------------------------------------
-// Walktrap v0.2 -- Finds community structure of networks using random walks
-// Copyright (C) 2004-2005 Pascal Pons
-//
-// This program is free software; you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation; either version 2 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program; if not, write to the Free Software
-// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-//-----------------------------------------------------------------------------
-// Author   : Pascal Pons 
-// Email    : pons@liafa.jussieu.fr
-// Web page : http://www.liafa.jussieu.fr/~pons/
-// Location : Paris, France
-// Time	    : June 2005
-//-----------------------------------------------------------------------------
-// see readme.txt for more details
-
-#include <iostream>
-#include <fstream>
-#include <sstream>
-#include "graph.h"
-
-using namespace std;
-
-
-bool operator<(const Edge& E1, const Edge& E2) {
-  return(E1.neighbor < E2.neighbor);
-}
-
-
-Vertex::Vertex() {
-  degree = 0;
-  edges = 0;
-  total_weight = 0.;
-}
-
-Vertex::~Vertex() {
-  if(edges) delete[] edges;
-}
-
-Graph::Graph() {
-  nb_vertices = 0;
-  nb_edges = 0;
-  vertices = 0;
-  index = 0;
-  total_weight = 0.;
-}
-
-Graph::~Graph () {
-  if (vertices) delete[] vertices;
-}
-
-class Edge_list {  
-public:
-  int* V1;
-  int* V2;
-  float* W;
-
-  int size;
-  int size_max;
-  
-  void add(int v1, int v2, float w);
-  Edge_list() {
-    size = 0;
-    size_max = 1024;
-    V1 = new int[1024];
-    V2 = new int[1024];
-    W = new float[1024];
-  }
-  ~Edge_list() {
-    if(V1) delete[] V1;
-    if(V2) delete[] V2;
-    if(W) delete[] W;
-  }
-};
-
-void Edge_list::add(int v1, int v2, float w) {
-  if(size == size_max) {
-    int* tmp1 = new int[2*size_max];
-    int* tmp2 = new int[2*size_max];
-    float* tmp3 = new float[2*size_max];
-    for(int i = 0; i < size_max; i++) {
-      tmp1[i] = V1[i];
-      tmp2[i] = V2[i];      
-      tmp3[i] = W[i];
-    }
-    delete[] V1;
-    delete[] V2;
-    delete[] W;
-    V1 = tmp1;
-    V2 = tmp2;
-    W = tmp3;
-    size_max *= 2;
-  }
-  V1[size] = v1;
-  V2[size] = v2;
-  W[size] = w;
-  size++;
-}
-
-
-
-
-istream& operator>>(istream& stream, Graph& G) {
-  if(G.vertices) delete[] G.vertices;
-
-  int nb_line = 0;
-  int max_vertex = 0;
-  
-  Edge_list EL;
-
-  while (!stream.eof()) {	// loop for each line of the file
-    nb_line++;
-    string str;
-    getline(stream, str);
-    if(str[0] == '#') continue;	// a comment line
-    istringstream line(str);
-
-    int v1;
-    line >> v1;
-    if(line.fail()) {
-      if(line.eof()) continue;
-      cerr << "error : unable to read line " << nb_line << " : " << str << endl;
-      exit(0);
-    }
-    int v2;
-    line >> v2;
-    if(line.fail()) {
-      cerr << "error : unable to read line " << nb_line << " : " << str << endl;
-      exit(0);
-    }
-    float w;
-    line >> w;
-    if(line.fail()) {
-      if(line.eof()) w = 1.;
-      else {
-	cerr << "error : unable to read line " << nb_line << " : " << str << endl;
-	exit(0);
-      }
-    }
-    if(!line.eof()) {
-      cerr << "error : line " << nb_line << " too long : " << str << endl;
-      exit(0);
-    }
-
-    if(v1 > max_vertex) max_vertex = v1;
-    if(v2 > max_vertex) max_vertex = v2;
-    if((v1 < 0) || (v2 < 0)) {
-      cerr << "error : line " << nb_line << " negative vertex number : " << str << endl;
-      exit(0);
-    }
-    if(w < 0) {
-      cerr << "error : line " << nb_line << " negative weight : " << str << endl;
-      exit(0);
-    }
-    EL.add(v1, v2, w);
-  }
-
-  G.nb_vertices = max_vertex + 1; 
-  G.vertices = new Vertex[G.nb_vertices];
-  G.nb_edges = 0;
-  G.total_weight = 0.;
-
-  for(int i = 0; i < EL.size; i++) {
-      G.vertices[EL.V1[i]].degree++;
-      G.vertices[EL.V2[i]].degree++;
-      G.vertices[EL.V1[i]].total_weight += EL.W[i];
-      G.vertices[EL.V2[i]].total_weight += EL.W[i];
-      G.nb_edges++;
-      G.total_weight += EL.W[i];
-    }
-
-  for(int i = 0; i < G.nb_vertices; i++) {
-    if(G.vertices[i].degree == 0) {
-      cerr << "error : degree of vertex " << i << " is 0" << endl;
-      exit(0);
-    }
-    G.vertices[i].edges = new Edge[G.vertices[i].degree + 1];
-    G.vertices[i].edges[0].neighbor = i;
-    G.vertices[i].edges[0].weight = G.vertices[i].total_weight/double(G.vertices[i].degree);
-    G.vertices[i].total_weight+= G.vertices[i].total_weight/double(G.vertices[i].degree);
-    G.vertices[i].degree = 1;
-  }
- 
-  for(int i = 0; i < EL.size; i++) {
-    G.vertices[EL.V1[i]].edges[G.vertices[EL.V1[i]].degree].neighbor = EL.V2[i];
-    G.vertices[EL.V1[i]].edges[G.vertices[EL.V1[i]].degree].weight = EL.W[i];
-    G.vertices[EL.V1[i]].degree++;
-    G.vertices[EL.V2[i]].edges[G.vertices[EL.V2[i]].degree].neighbor = EL.V1[i];
-    G.vertices[EL.V2[i]].edges[G.vertices[EL.V2[i]].degree].weight = EL.W[i];
-    G.vertices[EL.V2[i]].degree++;
-  }  
-  
-  for(int i = 0; i < G.nb_vertices; i++)
-    sort(G.vertices[i].edges, G.vertices[i].edges+G.vertices[i].degree);
-
-  for(int i = 0; i < G.nb_vertices; i++) {  // merge multi edges
-    int a = 0;
-    for(int b = 1; b < G.vertices[i].degree; b++) {
-      if(G.vertices[i].edges[b].neighbor == G.vertices[i].edges[a].neighbor)
-	G.vertices[i].edges[a].weight += G.vertices[i].edges[b].weight;
-      else 
-	G.vertices[i].edges[++a] = G.vertices[i].edges[b];
-    }
-    G.vertices[i].degree = a+1;
-  }
-
-  return stream;
-}
-
-
-long Graph::memory() {
-  long m = 0;
-  m += long(nb_vertices)*sizeof(Vertex);
-  m += 2*long(nb_edges)*sizeof(Edge);
-  m += sizeof(Graph);
-  if(index != 0) {
-    m += long(nb_vertices)*sizeof(char*);
-    for(int i = 0; i < nb_vertices; i++)
-      m += strlen(index[i]) + 1;
-  }
-  return m;
-}
-
-
-bool Graph::load_index(char* input_file) {
-  ifstream f;
-  f.open(input_file, ios::in);
-  if(!f.is_open()) {
-    cerr << "unable to open file " << index << " , index is ignored" << endl; 
-    return false;
-  }
-  index = new char*[nb_vertices];
-  for(int i = 0; i < nb_vertices; ++i)
-    index[i] = 0;
-   
-  int nb_line = 0;
-  while (!f.eof()) {	// loop for each line of the file
-    nb_line++;
-    int i;
-    f >> i;
-    if(f.fail()) {
-      if(f.eof()) break;
-      cerr << "error : unable to read line " << nb_line << " , index is ignored" << endl;
-      for(int i = 0; i < nb_vertices; ++i)
-	if(index[i]) delete[] index[i];
-      delete[] index;
-      index = 0;
-      return false;
-    }
-    if(i < 0 || i >= nb_vertices || index[i] != 0) {
-      cerr << "error : invalid vertex number at line : " << nb_line << " , index is ignored" << endl;
-      for(int i = 0; i < nb_vertices; ++i)
-	if(index[i]) delete[] index[i];
-      delete[] index;
-      index = 0;
-      return false;
-    }
-    string str;
-    getline(f, str);
-    if(str.length() <= 1) {
-      cerr << "error : unable to read line " << nb_line << " , index is ignored" << endl;
-      for(int i = 0; i < nb_vertices; ++i)
-	if(index[i]) delete[] index[i];
-      delete[] index;
-      index = 0;
-      return false;
-    }
-    char* c = new char[str.size()];
-    strcpy(c, str.c_str()+1);
-    index[i] = c;
-  }
-  
-  for(int i = 0; i < nb_vertices; ++i)
-    if(index[i] == 0) {
-      cerr << "error : vertex " << i << "not found, index is ignored" << endl;
-      for(int i = 0; i < nb_vertices; ++i)
-	if(index[i]) delete[] index[i];
-      delete[] index;
-      index = 0;
-      return false;
-    }
-  return true;
-}
-
-
-
-
-
-
-
-
-
-
-
-
-
-
+// File: graph.cpp
+//-----------------------------------------------------------------------------
+// Walktrap v0.2 -- Finds community structure of networks using random walks
+// Copyright (C) 2004-2005 Pascal Pons
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//-----------------------------------------------------------------------------
+// Author   : Pascal Pons 
+// Email    : pons@liafa.jussieu.fr
+// Web page : http://www.liafa.jussieu.fr/~pons/
+// Location : Paris, France
+// Time	    : June 2005
+//-----------------------------------------------------------------------------
+// see readme.txt for more details
+
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include "graph.h"
+
+using namespace std;
+
+
+bool operator<(const Edge& E1, const Edge& E2) {
+  return(E1.neighbor < E2.neighbor);
+}
+
+
+Vertex::Vertex() {
+  degree = 0;
+  edges = 0;
+  total_weight = 0.;
+}
+
+Vertex::~Vertex() {
+  if(edges) delete[] edges;
+}
+
+Graph::Graph() {
+  nb_vertices = 0;
+  nb_edges = 0;
+  vertices = 0;
+  index = 0;
+  total_weight = 0.;
+}
+
+Graph::~Graph () {
+  if (vertices) delete[] vertices;
+}
+
+class Edge_list {  
+public:
+  int* V1;
+  int* V2;
+  float* W;
+
+  int size;
+  int size_max;
+  
+  void add(int v1, int v2, float w);
+  Edge_list() {
+    size = 0;
+    size_max = 1024;
+    V1 = new int[1024];
+    V2 = new int[1024];
+    W = new float[1024];
+  }
+  ~Edge_list() {
+    if(V1) delete[] V1;
+    if(V2) delete[] V2;
+    if(W) delete[] W;
+  }
+};
+
+void Edge_list::add(int v1, int v2, float w) {
+  if(size == size_max) {
+    int* tmp1 = new int[2*size_max];
+    int* tmp2 = new int[2*size_max];
+    float* tmp3 = new float[2*size_max];
+    for(int i = 0; i < size_max; i++) {
+      tmp1[i] = V1[i];
+      tmp2[i] = V2[i];      
+      tmp3[i] = W[i];
+    }
+    delete[] V1;
+    delete[] V2;
+    delete[] W;
+    V1 = tmp1;
+    V2 = tmp2;
+    W = tmp3;
+    size_max *= 2;
+  }
+  V1[size] = v1;
+  V2[size] = v2;
+  W[size] = w;
+  size++;
+}
+
+
+
+
+istream& operator>>(istream& stream, Graph& G) {
+  if(G.vertices) delete[] G.vertices;
+
+  int nb_line = 0;
+  int max_vertex = 0;
+  
+  Edge_list EL;
+
+  while (!stream.eof()) {	// loop for each line of the file
+    nb_line++;
+    string str;
+    getline(stream, str);
+    if(str[0] == '#') continue;	// a comment line
+    istringstream line(str);
+
+    int v1;
+    line >> v1;
+    if(line.fail()) {
+      if(line.eof()) continue;
+      cerr << "error : unable to read line " << nb_line << " : " << str << endl;
+      exit(0);
+    }
+    int v2;
+    line >> v2;
+    if(line.fail()) {
+      cerr << "error : unable to read line " << nb_line << " : " << str << endl;
+      exit(0);
+    }
+    float w;
+    line >> w;
+    if(line.fail()) {
+      if(line.eof()) w = 1.;
+      else {
+	cerr << "error : unable to read line " << nb_line << " : " << str << endl;
+	exit(0);
+      }
+    }
+    if(!line.eof()) {
+      cerr << "error : line " << nb_line << " too long : " << str << endl;
+      exit(0);
+    }
+
+    if(v1 > max_vertex) max_vertex = v1;
+    if(v2 > max_vertex) max_vertex = v2;
+    if((v1 < 0) || (v2 < 0)) {
+      cerr << "error : line " << nb_line << " negative vertex number : " << str << endl;
+      exit(0);
+    }
+    if(w < 0) {
+      cerr << "error : line " << nb_line << " negative weight : " << str << endl;
+      exit(0);
+    }
+    EL.add(v1, v2, w);
+  }
+
+  G.nb_vertices = max_vertex + 1; 
+  G.vertices = new Vertex[G.nb_vertices];
+  G.nb_edges = 0;
+  G.total_weight = 0.;
+
+  for(int i = 0; i < EL.size; i++) {
+      G.vertices[EL.V1[i]].degree++;
+      G.vertices[EL.V2[i]].degree++;
+      G.vertices[EL.V1[i]].total_weight += EL.W[i];
+      G.vertices[EL.V2[i]].total_weight += EL.W[i];
+      G.nb_edges++;
+      G.total_weight += EL.W[i];
+    }
+
+  for(int i = 0; i < G.nb_vertices; i++) {
+    if(G.vertices[i].degree == 0) {
+      cerr << "error : degree of vertex " << i << " is 0" << endl;
+      exit(0);
+    }
+    G.vertices[i].edges = new Edge[G.vertices[i].degree + 1];
+    G.vertices[i].edges[0].neighbor = i;
+    G.vertices[i].edges[0].weight = G.vertices[i].total_weight/double(G.vertices[i].degree);
+    G.vertices[i].total_weight+= G.vertices[i].total_weight/double(G.vertices[i].degree);
+    G.vertices[i].degree = 1;
+  }
+ 
+  for(int i = 0; i < EL.size; i++) {
+    G.vertices[EL.V1[i]].edges[G.vertices[EL.V1[i]].degree].neighbor = EL.V2[i];
+    G.vertices[EL.V1[i]].edges[G.vertices[EL.V1[i]].degree].weight = EL.W[i];
+    G.vertices[EL.V1[i]].degree++;
+    G.vertices[EL.V2[i]].edges[G.vertices[EL.V2[i]].degree].neighbor = EL.V1[i];
+    G.vertices[EL.V2[i]].edges[G.vertices[EL.V2[i]].degree].weight = EL.W[i];
+    G.vertices[EL.V2[i]].degree++;
+  }  
+  
+  for(int i = 0; i < G.nb_vertices; i++)
+    sort(G.vertices[i].edges, G.vertices[i].edges+G.vertices[i].degree);
+
+  for(int i = 0; i < G.nb_vertices; i++) {  // merge multi edges
+    int a = 0;
+    for(int b = 1; b < G.vertices[i].degree; b++) {
+      if(G.vertices[i].edges[b].neighbor == G.vertices[i].edges[a].neighbor)
+	G.vertices[i].edges[a].weight += G.vertices[i].edges[b].weight;
+      else 
+	G.vertices[i].edges[++a] = G.vertices[i].edges[b];
+    }
+    G.vertices[i].degree = a+1;
+  }
+
+  return stream;
+}
+
+
+long Graph::memory() {
+  long m = 0;
+  m += long(nb_vertices)*sizeof(Vertex);
+  m += 2*long(nb_edges)*sizeof(Edge);
+  m += sizeof(Graph);
+  if(index != 0) {
+    m += long(nb_vertices)*sizeof(char*);
+    for(int i = 0; i < nb_vertices; i++)
+      m += strlen(index[i]) + 1;
+  }
+  return m;
+}
+
+
+bool Graph::load_index(char* input_file) {
+  ifstream f;
+  f.open(input_file, ios::in);
+  if(!f.is_open()) {
+    cerr << "unable to open file " << index << " , index is ignored" << endl; 
+    return false;
+  }
+  index = new char*[nb_vertices];
+  for(int i = 0; i < nb_vertices; ++i)
+    index[i] = 0;
+   
+  int nb_line = 0;
+  while (!f.eof()) {	// loop for each line of the file
+    nb_line++;
+    int i;
+    f >> i;
+    if(f.fail()) {
+      if(f.eof()) break;
+      cerr << "error : unable to read line " << nb_line << " , index is ignored" << endl;
+      for(int i = 0; i < nb_vertices; ++i)
+	if(index[i]) delete[] index[i];
+      delete[] index;
+      index = 0;
+      return false;
+    }
+    if(i < 0 || i >= nb_vertices || index[i] != 0) {
+      cerr << "error : invalid vertex number at line : " << nb_line << " , index is ignored" << endl;
+      for(int i = 0; i < nb_vertices; ++i)
+	if(index[i]) delete[] index[i];
+      delete[] index;
+      index = 0;
+      return false;
+    }
+    string str;
+    getline(f, str);
+    if(str.length() <= 1) {
+      cerr << "error : unable to read line " << nb_line << " , index is ignored" << endl;
+      for(int i = 0; i < nb_vertices; ++i)
+	if(index[i]) delete[] index[i];
+      delete[] index;
+      index = 0;
+      return false;
+    }
+    char* c = new char[str.size()];
+    strcpy(c, str.c_str()+1);
+    index[i] = c;
+  }
+  
+  for(int i = 0; i < nb_vertices; ++i)
+    if(index[i] == 0) {
+      cerr << "error : vertex " << i << "not found, index is ignored" << endl;
+      for(int i = 0; i < nb_vertices; ++i)
+	if(index[i]) delete[] index[i];
+      delete[] index;
+      index = 0;
+      return false;
+    }
+  return true;
+}
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff -ru walktrap_clean/graph.h walktrap/graph.h
--- walktrap_clean/graph.h	2005-06-07 14:18:46.000000000 +0200
+++ walktrap/graph.h	2009-12-03 17:04:10.000000000 +0100
@@ -1,71 +1,74 @@
-// File: graph.h
-//-----------------------------------------------------------------------------
-// Walktrap v0.2 -- Finds community structure of networks using random walks
-// Copyright (C) 2004-2005 Pascal Pons
-//
-// This program is free software; you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation; either version 2 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program; if not, write to the Free Software
-// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-//-----------------------------------------------------------------------------
-// Author   : Pascal Pons 
-// Email    : pons@liafa.jussieu.fr
-// Web page : http://www.liafa.jussieu.fr/~pons/
-// Location : Paris, France
-// Time	    : June 2005
-//-----------------------------------------------------------------------------
-// see readme.txt for more details
-
-
-#ifndef GRAPH_H
-#define GRAPH_H
-#include <iostream>
-
-using namespace std;
-
-class Edge {			// code an edge of a given vertex
-public:
-  int neighbor;			// the number of the neighbor vertex
-  float weight;			// the weight of the edge
-};
-bool operator<(const Edge& E1, const Edge& E2);
-
-
-class Vertex {
-public:
-  Edge* edges;			// the edges of the vertex
-  int degree;			// number of neighbors
-  float total_weight;		// the total weight of the vertex
-
-  Vertex();			// creates empty vertex
-  ~Vertex();			// destructor
-};
-
-class Graph {
-public:
-  int nb_vertices;		// number of vertices
-  int nb_edges;			// number of edges
-  float total_weight;		// total weight of the edges
-  Vertex* vertices;		// array of the vertices
-
-  long memory();			// the total memory used in Bytes
-  Graph();			// create an empty graph
-  ~Graph();			// destructor
-  char** index;			// to keep the real name of the vertices
-  bool load_index(char* input_file);
-};
-
-istream& operator>>(istream& in, Graph& G);	// get a graph from a stream
-
-
-#endif
-
+// File: graph.h
+//-----------------------------------------------------------------------------
+// Walktrap v0.2 -- Finds community structure of networks using random walks
+// Copyright (C) 2004-2005 Pascal Pons
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//-----------------------------------------------------------------------------
+// Author   : Pascal Pons 
+// Email    : pons@liafa.jussieu.fr
+// Web page : http://www.liafa.jussieu.fr/~pons/
+// Location : Paris, France
+// Time	    : June 2005
+//-----------------------------------------------------------------------------
+// see readme.txt for more details
+
+
+#ifndef GRAPH_H
+#define GRAPH_H
+#include <iostream>
+#include <cstdlib>
+#include <algorithm>
+#include <cstring>
+
+using namespace std;
+
+class Edge {			// code an edge of a given vertex
+public:
+  int neighbor;			// the number of the neighbor vertex
+  float weight;			// the weight of the edge
+};
+bool operator<(const Edge& E1, const Edge& E2);
+
+
+class Vertex {
+public:
+  Edge* edges;			// the edges of the vertex
+  int degree;			// number of neighbors
+  float total_weight;		// the total weight of the vertex
+
+  Vertex();			// creates empty vertex
+  ~Vertex();			// destructor
+};
+
+class Graph {
+public:
+  int nb_vertices;		// number of vertices
+  int nb_edges;			// number of edges
+  float total_weight;		// total weight of the edges
+  Vertex* vertices;		// array of the vertices
+
+  long memory();			// the total memory used in Bytes
+  Graph();			// create an empty graph
+  ~Graph();			// destructor
+  char** index;			// to keep the real name of the vertices
+  bool load_index(char* input_file);
+};
+
+istream& operator>>(istream& in, Graph& G);	// get a graph from a stream
+
+
+#endif
+