Ejemplo n.º 1
0
    // Add the fact that v1 and v2 are equivalent
    // return true if v1 was not already equivalent to v2
    // and false if v1 was already equivalent to v2
    bool SetEquivalent(int v1, int v2)
    {
      bool const already_equiv = false;
      if (v1 == v2) 
	return already_equiv;
      ensureElementExists(v1);
      ensureElementExists(v2);

      
      const int r1 = disjoint_sets_.find_set(v1);
      const int r2 = disjoint_sets_.find_set(v2);
      if (r1 == r2) 
	return already_equiv;
      root_set_map_t::const_iterator it1 = rootSetMap_.find(r1);
      assert(it1 != rootSetMap_.end());
      std::list<int> s1 = it1->second;

      root_set_map_t::const_iterator  it2 = rootSetMap_.find(r2);
      assert(it2 != rootSetMap_.end());
      std::list<int> s2 = it2->second;

      s1.splice(s1.begin(), s2); // union the related sets

      disjoint_sets_.link(r1, r2); // union the disjoint sets

      // associate the combined related set with the new root
      int const new_root = disjoint_sets_.find_set(v1);
      if (new_root != r1) {
	rootSetMap_.erase(it1);
      } else {
	rootSetMap_.erase(it2);
      }
      rootSetMap_[new_root] = s1;
      return !already_equiv;
    }
Ejemplo n.º 2
0
    // Return true if v1 and v2 are equivalent
    bool AreEquivalent(int v1, int v2) const
    {
      if (v1 == v2) {
	return true;
      }

      // The element does not exist, so we do not
      // know any equivalence information,
      // hence, v1 and v2 are not equivalent.
      if (!elementExists(v1) || !elementExists(v2)) {
	return false;
      }

      return disjoint_sets_.find_set(v1) == disjoint_sets_.find_set(v2);
    }
Ejemplo n.º 3
0
	void __output_ancestors(Vertex from, Vertex const u, Vertex const v) {
		sets.make_set(from);
		ancestors[sets.find_set(from)] = from;
		VertexContainer child = children(from);
		for (VertexContainer::iterator ite = child.begin(); ite != child.end(); ++ite) {
			__output_ancestors(*ite, u, v);
			sets.union_set(from, *ite);
			ancestors[sets.find_set(from)] = from;
		}
		colors[from] = black;
		if (u == from && colors[v] == black) {
			printf("The least common ancestor of %d and %d is %d.\n",
				query_dat(u), query_dat(v), query_dat(ancestors[sets.find_set(v)]));
		}
		else if (v == from && colors[u] == black) {
			printf("The least common ancestor of %d and %d is %d.\n",
				query_dat(v), query_dat(u), query_dat(ancestors[sets.find_set(u)]));
		}
	}
Ejemplo n.º 4
0
    // Return the representative for the node v.
    int FindSet(int v) const
    {
      // If element does not exist
      if (!elementExists(v)) {
	// Then it is its own root.
	// This avoids adding singleton sets to the partition.
	return v;
      }

      return disjoint_sets_.find_set(v);
    }
Ejemplo n.º 5
0
    // Return a list of elements that are in the same disjoint set
    // as v.
    std::list<int> GetRelatedSet(int v) const
    {
      std::list<int> ret;
      if (!elementExists(v)) {
	ret.push_back(v);
	return ret;
      }
      int root = disjoint_sets_.find_set(v);
      root_set_map_t::const_iterator it = rootSetMap_.find(root);
      assert(it!=rootSetMap_.end());
      return it->second;
    }