generate ordering by breadth-first-search, a lot faster than before
parent
8d22b3aca2
commit
215ff24d0f
|
@ -9,6 +9,8 @@
|
|||
#include <boost/assign/std/list.hpp> // for operator +=
|
||||
#include <boost/foreach.hpp>
|
||||
#include <boost/tuple/tuple.hpp>
|
||||
#include <boost/graph/adjacency_list.hpp>
|
||||
#include <boost/graph/breadth_first_search.hpp>
|
||||
|
||||
#include "Ordering.h"
|
||||
|
||||
|
@ -18,40 +20,56 @@ using namespace boost::assign;
|
|||
|
||||
#define FOREACH_PAIR( KEY, VAL, COL) BOOST_FOREACH (boost::tie(KEY,VAL),COL)
|
||||
|
||||
class key_visitor : public boost::default_bfs_visitor {
|
||||
public:
|
||||
key_visitor(Ordering& ordering_in) : ordering_(ordering_in) {}
|
||||
template <typename Vertex, typename Graph> void discover_vertex(Vertex u, const Graph& g) const {
|
||||
string key = boost::get(boost::vertex_name, g, u);
|
||||
ordering_.push_front(key);
|
||||
}
|
||||
Ordering& ordering_;
|
||||
};
|
||||
|
||||
/* ************************************************************************* */
|
||||
Ordering::Ordering(const map<string, string>& p_map) {
|
||||
|
||||
// find the root
|
||||
string root;
|
||||
bool foundRoot = false;
|
||||
typedef boost::adjacency_list<
|
||||
boost::vecS, boost::vecS, boost::undirectedS,
|
||||
boost::property<boost::vertex_name_t, string> > Graph;
|
||||
typedef boost::graph_traits<Graph>::vertex_descriptor Vertex;
|
||||
|
||||
// build the graph corresponding to the predecessor map
|
||||
Graph g(0);
|
||||
map<string, Vertex> key2vertex;
|
||||
Vertex v1, v2, root;
|
||||
string child, parent;
|
||||
bool foundRoot = false;
|
||||
FOREACH_PAIR(child, parent, p_map) {
|
||||
if (key2vertex.find(child) == key2vertex.end()) {
|
||||
v1 = add_vertex(child, g);
|
||||
key2vertex.insert(make_pair(child, v1));
|
||||
} else
|
||||
v1 = key2vertex[child];
|
||||
|
||||
if (key2vertex.find(parent) == key2vertex.end()) {
|
||||
v2 = add_vertex(parent, g);
|
||||
key2vertex.insert(make_pair(parent, v2));
|
||||
} else
|
||||
v2 = key2vertex[parent];
|
||||
|
||||
if (child.compare(parent) == 0) {
|
||||
root = child;
|
||||
root = v1;
|
||||
foundRoot = true;
|
||||
break;
|
||||
}
|
||||
} else
|
||||
boost::add_edge(v1, v2, g);
|
||||
}
|
||||
push_front(root);
|
||||
|
||||
if (!foundRoot)
|
||||
throw invalid_argument("Ordering: invalid predecessor map!");
|
||||
|
||||
// push front the nodes from the root level to the leaf level
|
||||
list<string> parents(1, root);
|
||||
while(!parents.empty()){
|
||||
list<string> children;
|
||||
BOOST_FOREACH(string key, parents){
|
||||
FOREACH_PAIR(child, parent, p_map){
|
||||
if (parent.compare(key)==0 && child.compare(key)!=0) {
|
||||
children.push_back(child);
|
||||
push_front(child);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
parents = children;
|
||||
}
|
||||
// breadth first visit on the graph
|
||||
key_visitor vis(*this);
|
||||
boost::breadth_first_search(g, root, boost::visitor(vis));
|
||||
}
|
||||
|
||||
/* ************************************************************************* */
|
||||
|
|
Loading…
Reference in New Issue