89 lines
2.2 KiB
C++
89 lines
2.2 KiB
C++
|
// (C) Copyright Jeremy Siek 2004
|
||
|
|
// Distributed under the Boost Software License, Version 1.0. (See
|
||
|
|
// accompanying file LICENSE_1_0.txt or copy at
|
||
|
|
// http://www.boost.org/LICENSE_1_0.txt)
|
||
|
|
|
||
|
|
#ifndef BOOST_DETAIL_DISJOINT_SETS_HPP
|
||
|
|
#define BOOST_DETAIL_DISJOINT_SETS_HPP
|
||
|
|
|
||
|
|
namespace boost {
|
||
|
|
|
||
|
|
namespace detail {
|
||
|
|
|
||
|
|
template <class ParentPA, class Vertex>
|
||
|
|
Vertex
|
||
|
|
find_representative_with_path_halving(ParentPA p, Vertex v)
|
||
|
|
{
|
||
|
|
Vertex parent = get(p, v);
|
||
|
|
Vertex grandparent = get(p, parent);
|
||
|
|
while (parent != grandparent) {
|
||
|
|
put(p, v, grandparent);
|
||
|
|
v = grandparent;
|
||
|
|
parent = get(p, v);
|
||
|
|
grandparent = get(p, parent);
|
||
|
|
}
|
||
|
|
return parent;
|
||
|
|
}
|
||
|
|
|
||
|
|
template <class ParentPA, class Vertex>
|
||
|
|
Vertex
|
||
|
|
find_representative_with_full_compression(ParentPA parent, Vertex v)
|
||
|
|
{
|
||
|
|
Vertex old = v;
|
||
|
|
Vertex ancestor = get(parent, v);
|
||
|
|
while (ancestor != v) {
|
||
|
|
v = ancestor;
|
||
|
|
ancestor = get(parent, v);
|
||
|
|
}
|
||
|
|
v = get(parent, old);
|
||
|
|
while (ancestor != v) {
|
||
|
|
put(parent, old, ancestor);
|
||
|
|
old = v;
|
||
|
|
v = get(parent, old);
|
||
|
|
}
|
||
|
|
return ancestor;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* the postcondition of link sets is:
|
||
|
|
component_representative(i) == component_representative(j)
|
||
|
|
*/
|
||
|
|
template <class ParentPA, class RankPA, class Vertex,
|
||
|
|
class ComponentRepresentative>
|
||
|
|
inline void
|
||
|
|
link_sets(ParentPA p, RankPA rank, Vertex i, Vertex j,
|
||
|
|
ComponentRepresentative comp_rep)
|
||
|
|
{
|
||
|
|
i = comp_rep(p, i);
|
||
|
|
j = comp_rep(p, j);
|
||
|
|
if (i == j) return;
|
||
|
|
if (get(rank, i) > get(rank, j))
|
||
|
|
put(p, j, i);
|
||
|
|
else {
|
||
|
|
put(p, i, j);
|
||
|
|
if (get(rank, i) == get(rank, j))
|
||
|
|
put(rank, j, get(rank, j) + 1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// normalize components has the following postcondidition:
|
||
|
|
// i >= p[i]
|
||
|
|
// that is, the representative is the node with the smallest index in its class
|
||
|
|
// as its precondition it it assumes that the node container is compressed
|
||
|
|
|
||
|
|
template <class ParentPA, class Vertex>
|
||
|
|
inline void
|
||
|
|
normalize_node(ParentPA p, Vertex i)
|
||
|
|
{
|
||
|
|
if (i > get(p,i) || get(p, get(p,i)) != get(p,i))
|
||
|
|
put(p,i, get(p, get(p,i)));
|
||
|
|
else {
|
||
|
|
put(p, get(p,i), i);
|
||
|
|
put(p, i, i);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace detail
|
||
|
|
} // namespace boost
|
||
|
|
|
||
|
|
#endif // BOOST_DETAIL_DISJOINT_SETS_HPP
|