Bonjour,Dear all I am facing general programming related logical error. I want to access bolean variable of the class by using get method. but it is not giving the right result. When i read the counter and boolean variable by getcount() and isPathExist() methods. Each time it returns "0" for counter and false for boolean. My code is below #include "AlgoPC.h"#include <boost/graph/depth_first_search.hpp> //=============================Depth First Search===========================class DFSVisitor: public default_dfs_visitor {protected: slBayesianNetwork *pBN; int nodeA, nodeC; bool exist; int counter; public: DFSVisitor(slBayesianNetwork *pBN, int nodeA, int nodeC); ~DFSVisitor(); void discover_vertex(slNode u, const slGraph &g); void resetCounter(); bool isPathExist(); int getCounter(); };//-------------------------------------------------------------------------- DFSVisitor::DFSVisitor(slBayesianNetwork *pBN, int nodeA, int nodeC) { this->pBN = pBN; this->nodeA = nodeA; this->nodeC = nodeC; this->exist = false; this->resetCounter(); }//-------------------------------------------------------------------------- DFSVisitor::~DFSVisitor() { }//--------------------------------------------------------------------------void DFSVisitor::resetCounter() { this->counter = 0; }//-------------------------------------------------------------------------- //--------------------------------------------------------------------------void DFSVisitor::discover_vertex(slNode u, const slGraph &g) { this->counter++; unsigned int varIdx = this->pBN->getVariableIndex(u); if ((varIdx == this->nodeC ) && ((this->counter) > 2)) { this->exist = true; cout<<"\n "<<counter<<" node = "<< varIdx+1; } }//--------------------------------------------------------------------------int DFSVisitor::getCounter() { return this->counter; }//--------------------------------------------------------------------------bool DFSVisitor::isPathExist() { return this->exist; } ====================== main program ======================= cout<< "\n a = "<<a<<" c = "<<c; DFSVisitor vis(this->pBN, a , c); depth_first_search((slGraph&)this->pBN->get_graph(),visitor(vis).root_vertex(vertex(a, this->pBN->get_graph()))); cout<<"\n counter is = "<<vis.getCounter()<<" Path exist = "<< vis.isPathExist(); ======================== out put ========================= counter is = 0 path exist = 0 (false) ------------------------------------------------------- I will be thankful to you for guiding me. Best Regards Amanullah YASIN Master2 (ECD) Ecole Polytechnique Université de Nantes, France. Mob# 06 47 62 89 96 Fix # 02 72 00 26 45 amanyasin@gmail.com