boost graph --- 有向图中两点间所有路径(可处理有环情况)

求有向图中两点间所有路径

DFS 递归版

typedef boost::graph_traits<graphtype>::vertex_descriptor vertex_t;

void AllPaths(vector<vector<vertex_t> >& res, vector<vertex_t> previous, vertex_t curr, vertex_t des){
for(unsigned int i = 0; i < previous.size(); ++i ){//寻找是否有环
if(previous[i] == curr){
return ;
}
}
previous.push_back(curr); //加入路径
if(curr == des){   //找到一条路径
res.push_back(previous);
}
typename graph_traits<graphtype>::out_edge_iterator out_i,out_end;
tie(out_i, out_end) = out_edges(curr, graph_);
for(; out_i != out_end; ++out_i ){
vertex_t v = target(*out_i, graph_);
AllPaths(res, previous, v, des);
}
}

DFS 非递归版

void AllPaths(vector<vector<vertex_t> >& res, vertex_t start, vertex_t end){
boost::unordered_map<vertex_t, boost::shared_ptr<std::set<vertex_t> > > visited;
vector<vertex_t> path;
typename boost::graph_traits<graphtype>::out_edge_iterator out_i, out_end;
path.push_back(start);
vertex_t top = path.back();
while(!path.empty()){
tie(out_i, out_end) = out_edges(top, graph_);
for(; out_i != out_end; ++out_i){
vertex_t v_tg = target(*out_i, graph_);
if(!IsExist(visited, top, v_tg)){
if(!IsExist(path, v_tg)){
path.push_back(v_tg);

visited[top]->insert(v_tg);
top = v_tg;
if(v_tg == end){ //找到路径
res.push_back(path);
path.pop_back();   //回溯
top = path.back();
}

}else{
path.pop_back();
top = path.back();
}
break;
}
}
if(out_i == out_end){
path.pop_back();
top = path.back();
}
}
}

bool IsExist(const vector<vertex_t>& src, vertex_t v){
vector<vertex_t>::const_iterator iter = src.begin();
for(; iter != src.end(); ++iter){
if(*iter == v){
return true;
}
}
return false;
}
bool IsExist(boost::unordered_map<vertex_t, boost::shared_ptr<std::set<vertex_t> > >& visited, vertex_t s, vertex_t v){
boost::unordered_map<vertex_t, boost::shared_ptr<std::set<vertex_t > > >::iterator map_iter = visited.find(s);
if(map_iter == visited.end()){
boost::shared_ptr<std::set<vertex_t> > vertexs(new set<vertex_t>());
visited.insert(std::make_pair(s, vertexs));

return false;
}else{
std::set<vertex_t>::const_iterator iter = map_iter->second->find(v);
if(iter == map_iter->second->end()){
return false;
}
return true;
}

}