boost-graph

问题 I am trying to write a program which uses the boost graph library to construct a graph from a text file and then perform certain algorithms of the user's choice on it. My code runs fine, but once boost::dijkstra_shortest_paths() or boost::prim_minimum_spanning_tree() finishes executing, the predecessor property for each vertex is set to that self-same vertex! It's like the algorithm runs without doing its job. I am rather unsure why this is happening, and was wondering if someone could shine

问题 I'm trying to migrate from a proprietary graph library to an Open Source one. EDIT: since so few people seem to know how Boost Graph actually works, if you can provide a solution using the LEMON Graph Library, that's fine too. Currently, my vertices have type Graph_Vertex* and can have an associated void* pointer to store related information. A similar logic is used with respect to edges, which are of type Graph_Edge* . I use the void* pointer to store my own structure Node_State , which is

问题 I'm new in using C++ boost library in particularly the boost graph library which a needed to try coding some algorithms where i commonly check the adjacency of two vertices and dealing with other graph concepts like computing graph invariants. What i know is that we can iterate through adjacent vertices with the function : adjacent_vertices(u, g) but i'm searching for an efficient way to test if two vertices u, v are adjacent or not without doing linear search 回答1: The AdjacencyMatrix concept

问题 I have the following code that generates an undirected graph: // --- Header File --- class Node { ... }; struct Edge { float weight; }; typedef adjacency_list<vecS, vecS, undirectedS, Node, Edge> Grafo; class MST { public: MST(std::vector<Node> nodes); Grafo g; vector<edge_t> build(); }; // --- cpp File --- MST::MST(std::vector<Node> nodes) { // build the graph by setting vertices and edges... } vector<edge_t> MST::build() { vector<edge_t> mst; kruskal_minimum_spanning_tree(g, std::back

问题 I want to run Dijkstra on a graph with blacklisted edges, i.e., I want to compute shortest paths that do not use those links. For the moment, I first define the filter: typedef std::pair<int, int> Edge; typedef boost::adjacency_list<boost::listS, boost::vecS, boost::directedS, boost::no_property, boost::property<boost::edge_weight_t, int> > graph_t; struct BlackListEdgeConstraint { private: std::set blackList; graph_t* g; public: BlackListEdgeConstraint():blackList(std::set<Edge>() ),g(NULL){

问题 I was wondering how the property maps are implemented in a boost Graph. For example, I have vertex and edge properties defined like this: //vertex property:--> struct NodeInfo { int a , b , c; }; //actual bundled property struct NodeInfoPropertyTag { // tag and kind (as in boost documentation) typedef boost::vertex_property_tag kind; static std::size_t const num; }; std::size_t const NodeInfoPropertyTag::num = (std::size_t) &NodeInfoPropertyTag::num; //typedef the Vertex Property typedef

问题 This question is loosely based on the Boost.Graph library (BGL) that uses a Visitor-like pattern to customize recursive (search) algorithms. The BGL passes visitor objects by value (in analogy with the STL function objects) and the documentation states Since the visitor parameter is passed by value, if your visitor contains state then any changes to the state during the algorithm will be made to a copy of the visitor object, not the visitor object passed in. Therefore you may want the visitor

问题 Why can't I compile the following simple app. If I changes listS to vecS every thing works just fine. (I'am using boost 1.46.1 and gcc 4.4.5) #include <iostream> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graphviz.hpp> int main(int argc, const char *argv[]) { boost::adjacency_list< boost::listS, boost::listS, boost::bidirectionalS > g; boost::write_graphviz(std::cout, g); return 0; } 回答1: write_graphviz needs the vertex_id property to display vertex identifier labels. An

问题 I am using Boost Graph library for some project and i want to find number of times an edge is repeated in a graph. for example, typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Node_Info, Edge_Info > Graph_t; //node_info and Edge_info are external node and edge properties (structures) suppose if i have two nodes, node1 and node2 and there is an edge between them (node1, node2). edge property for each edge contains a timestamp start, end.. and there can be many such

问题 Just trying to get my head around the Boost Graph Library and I have a few questions. I'm writing some code which is a wrapper class around a BGL graph. The idea is that I can manipulate the graph however I want, then call a wrapper method to output the graph in GEXF (XML) format. My code is something like this: struct Vertex { std::string label; ... }; struct Edge { std::string label; double weight; ... }; typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, Vertex, Edge