double scn::GetCyclicCoeff(UGraph::pGraph graph,size_t indexOfNode) { //IndexList edges; std::pair<IndexList, IndexList> result; std::unordered_map<size_t,size_t> distance; //auto& distance = distance_sssp; distance.clear(); if(indexOfNode != UGraph::NaF) {//one vertex result = graph->RemoveNode(indexOfNode); IndexList& edges = result.first; double sum = 0; for(auto head = edges.begin(); head != edges.end(); head++) { RunSPFA(graph,*head,distance); for(auto tail = head + 1; tail != edges.end(); tail++) { sum += 1.0 / static_cast<double>(distance[*tail] + 2); } } ///restore graph->AddEdge(graph->AddNode(indexOfNode), edges); return 2 * sum / static_cast<double>(edges.size() * (edges.size() - 1)); } else {//the whole network //copy node list IndexList nodes = graph->CopyIndexOfNodes(); double total_sum = 0; for(auto node = nodes.begin(); node != nodes.end(); node++) { result = graph->RemoveNode(*node); IndexList& edges = result.first; double sum = 0; for(auto head = edges.begin(); head != edges.end(); head++) { RunSPFA(graph,*head,distance); for(auto tail = head + 1; tail != edges.end(); tail++) { sum += 1.0 / static_cast<double>(distance[*tail] + 2); } } ///restore, add node first, then add list of edges of this node graph->AddEdge(graph->AddNode(*node), edges); //accumulate total_sum += 2 * sum / static_cast<double>(edges.size() * (edges.size() - 1)); } return total_sum / static_cast<double>(graph->GetNumberOfNodes()); } }
UGraph::pGraph scn::GenSmallWorldNetworkByNW(size_t numberOfNodes, size_t k, double probability) { assert(2* k + 1 <= numberOfNodes); assert(probability >= 0); assert(probability <= 1); //generate k-nearest network UGraph::pGraph graph = GenKNearestNetwork(numberOfNodes, k); //add edges randomly size_t numberOfEdges = numberOfNodes * (numberOfNodes - 2 * k - 1) / 2 * probability; size_t sum_edges = 0; size_t one, two; srand(size_t(time(00))); do { one = rand() % numberOfNodes; two = rand() % numberOfNodes; if(!(one == two || graph->HasEdge(one, two))) { graph->AddEdge(one, two); sum_edges++; } }while(sum_edges < numberOfEdges); return graph; }
double scn::GetVulnerability(UGraph::pGraph graph,size_t indexOfNode) { double original_efficiency = GetGlobalEfficiency(graph); std::pair<IndexList, IndexList> result; if(indexOfNode != Graph::NaF) {//compute the vulnerability of one node //remove the current node, note: only in_degree is used in //UGraph result = graph->RemoveNode(indexOfNode); IndexList& edges = result.first; //node edge double new_efficiency = GetGlobalEfficiency(graph); //restore the original graph graph->AddEdge(graph->AddNode(indexOfNode), edges); return (original_efficiency - new_efficiency) / original_efficiency; } else {//compute the vunlerability of the whole network IndexList setOfNode = graph->CopyIndexOfNodes(); //compute double max_vul = -1e200, new_vul; for(auto node = setOfNode.begin(); node != setOfNode.end(); node++) { //remove the current node, note: only in_degree is used in //UGraph result = graph->RemoveNode(*node); IndexList& edges = result.first; new_vul = (original_efficiency - GetGlobalEfficiency(graph)) / original_efficiency; if(new_vul > max_vul) max_vul = new_vul; //restore the original graph graph->AddEdge(graph->AddNode(*node), edges); } return max_vul; } }