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| // (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
|
|
