//======================================================================= // Copyright 1997, 1998, 1999, 2000 University of Notre Dame. // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek // // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) //======================================================================= #include #include #include #include #include #include using namespace std; using namespace boost; /* Exterior Decorator Basics An exterior decorator is a way of associating properties with the vertices or edges of a graph. The "exterior" part means that the properties are not stored inside the graph object (see internal_decorator_basics.cc). Instead they are stored separately, and passed as an extra argument to any algorithm they are needed in. There are several standard decorator types such a color and weight that are used in the GGCL algorithms. The main responsibility of a decorator is to provide an operator[] that maps a vertex (or vertex ID) to the property value for that vertex. It just so happens that a normal array provides this. In addition, a decorator must provide access to the property type through the decorator_traits class. For convenience, GGCL already defines a decorator_triats class for pointer and array types. Sample Output Jeremy owes Rich some money Jeremy owes Andrew some money Jeremy owes Jeff some money Jeremy owes Kinis some money Andrew owes Jeremy some money Andrew owes Kinis some money Jeff owes Jeremy some money Jeff owes Rich some money Jeff owes Kinis some money Kinis owes Jeremy some money Kinis owes Rich some money */ template void who_owes_who(EdgeIter first, EdgeIter last, const Graph& G, Name name) { while (first != last) { cout << name[source(*first,G)] << " owes " << name[target(*first,G)] << " some money" << endl; ++first; } } int main(int, char*[]) { /* The property will be "names" attached to the vertices */ string* names = new string[5]; names[0] = "Jeremy"; names[1] = "Rich"; names[2] = "Andrew"; names[3] = "Jeff"; names[4] = "Kinis"; typedef adjacency_list<> MyGraphType; typedef pair Pair; Pair edge_array[11] = { Pair(0,1), Pair(0,2), Pair(0,3), Pair(0,4), Pair(2,0), Pair(3,0), Pair(2,4), Pair(3,1), Pair(3,4), Pair(4,0), Pair(4,1) }; MyGraphType G(5); for (int i=0; i<11; ++i) add_edge(edge_array[i].first, edge_array[i].second, G); who_owes_who(edges(G).first, edges(G).second, G, names); return 0; }