Small improvements
Frank Dellaert
parent
48dd3cb769
commit
4e68feff37
|
|
@ -128,6 +128,12 @@ namespace gtsam {
|
||||||
root_(new Node(l, keyValue, r)) {
|
root_(new Node(l, keyValue, r)) {
|
||||||
}
|
}
|
||||||
|
|
||||||
|
/** assignment operator */
|
||||||
|
BTree & operator= (const BTree & other) {
|
||||||
|
root_ = other.root_;
|
||||||
|
return *this;
|
||||||
|
}
|
||||||
|
|
||||||
/** Check whether tree is empty */
|
/** Check whether tree is empty */
|
||||||
bool empty() const {
|
bool empty() const {
|
||||||
return !root_;
|
return !root_;
|
||||||
|
|
|
||||||
|
|
@ -27,147 +27,187 @@
|
||||||
|
|
||||||
namespace gtsam {
|
namespace gtsam {
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Disjoint Set Forest class
|
||||||
|
*
|
||||||
|
* Quoting from CLR: A disjoint-set data structure maintains a collection
|
||||||
|
* S = {S_1,S_2,...} of disjoint dynamic sets. Each set is identified by
|
||||||
|
* a representative, which is some member of the set.
|
||||||
|
*
|
||||||
|
* @addtogroup base
|
||||||
|
*/
|
||||||
|
template<class KEY>
|
||||||
|
class DSF: protected BTree<KEY, KEY> {
|
||||||
|
|
||||||
|
public:
|
||||||
|
typedef DSF<KEY> Self;
|
||||||
|
typedef std::set<KEY> Set;
|
||||||
|
typedef BTree<KEY, KEY> Tree;
|
||||||
|
typedef std::pair<KEY, KEY> KeyLabel;
|
||||||
|
|
||||||
|
// constructor
|
||||||
|
DSF() :
|
||||||
|
Tree() {
|
||||||
|
}
|
||||||
|
|
||||||
|
// constructor
|
||||||
|
DSF(const Tree& tree) :
|
||||||
|
Tree(tree) {
|
||||||
|
}
|
||||||
|
|
||||||
|
// constructor with a list of unconnected keys
|
||||||
|
DSF(const std::list<KEY>& keys) :
|
||||||
|
Tree() {
|
||||||
|
BOOST_FOREACH(const KEY& key, keys)
|
||||||
|
*this = this->add(key, key);
|
||||||
|
}
|
||||||
|
|
||||||
|
// constructor with a set of unconnected keys
|
||||||
|
DSF(const std::set<KEY>& keys) :
|
||||||
|
Tree() {
|
||||||
|
BOOST_FOREACH(const KEY& key, keys)
|
||||||
|
*this = this->add(key, key);
|
||||||
|
}
|
||||||
|
|
||||||
|
// create a new singleton, does nothing if already exists
|
||||||
|
Self makeSet(const KEY& key) const {
|
||||||
|
if (this->mem(key))
|
||||||
|
return *this;
|
||||||
|
else
|
||||||
|
return this->add(key, key);
|
||||||
|
}
|
||||||
|
|
||||||
|
// create a new singleton, does nothing if already exists
|
||||||
|
void makeSetInPlace(const KEY& key) {
|
||||||
|
if (!this->mem(key))
|
||||||
|
*this = this->add(key, key);
|
||||||
|
}
|
||||||
|
|
||||||
|
// find the label of the set in which {key} lives
|
||||||
|
KEY findSet(const KEY& key) const {
|
||||||
|
KEY parent = this->find(key);
|
||||||
|
return parent == key ? key : findSet(parent);
|
||||||
|
}
|
||||||
|
|
||||||
|
// return a new DSF where x and y are in the same set. No path compression
|
||||||
|
Self makeUnion(const KEY& key1, const KEY& key2) const {
|
||||||
|
DSF<KEY> copy = *this;
|
||||||
|
copy.makeUnionInPlace(key1,key2);
|
||||||
|
return copy;
|
||||||
|
}
|
||||||
|
|
||||||
|
// the in-place version of makeUnion
|
||||||
|
void makeUnionInPlace(const KEY& key1, const KEY& key2) {
|
||||||
|
*this = this->add(findSet_(key2), findSet_(key1));
|
||||||
|
}
|
||||||
|
|
||||||
|
// create a new singleton with two connected keys
|
||||||
|
Self makePair(const KEY& key1, const KEY& key2) const {
|
||||||
|
return makeSet(key1).makeSet(key2).makeUnion(key1, key2);
|
||||||
|
}
|
||||||
|
|
||||||
|
// create a new singleton with a list of fully connected keys
|
||||||
|
Self makeList(const std::list<KEY>& keys) const {
|
||||||
|
Self t = *this;
|
||||||
|
BOOST_FOREACH(const KEY& key, keys)
|
||||||
|
t = t.makePair(key, keys.front());
|
||||||
|
return t;
|
||||||
|
}
|
||||||
|
|
||||||
|
// return a dsf in which all find_set operations will be O(1) due to path compression.
|
||||||
|
DSF flatten() const {
|
||||||
|
DSF t = *this;
|
||||||
|
BOOST_FOREACH(const KeyLabel& pair, (Tree)t)
|
||||||
|
t.findSet_(pair.first);
|
||||||
|
return t;
|
||||||
|
}
|
||||||
|
|
||||||
|
// maps f over all keys, must be invertible
|
||||||
|
DSF map(boost::function<KEY(const KEY&)> func) const {
|
||||||
|
DSF t;
|
||||||
|
BOOST_FOREACH(const KeyLabel& pair, (Tree)*this)
|
||||||
|
t = t.add(func(pair.first), func(pair.second));
|
||||||
|
return t;
|
||||||
|
}
|
||||||
|
|
||||||
|
// return the number of sets
|
||||||
|
size_t numSets() const {
|
||||||
|
size_t num = 0;
|
||||||
|
BOOST_FOREACH(const KeyLabel& pair, (Tree)*this)
|
||||||
|
if (pair.first == pair.second)
|
||||||
|
num++;
|
||||||
|
return num;
|
||||||
|
}
|
||||||
|
|
||||||
|
// return the numer of keys
|
||||||
|
size_t size() const {
|
||||||
|
return Tree::size();
|
||||||
|
}
|
||||||
|
|
||||||
|
// return all sets, i.e. a partition of all elements
|
||||||
|
std::map<KEY, Set> sets() const {
|
||||||
|
std::map<KEY, Set> sets;
|
||||||
|
BOOST_FOREACH(const KeyLabel& pair, (Tree)*this)
|
||||||
|
sets[findSet(pair.second)].insert(pair.first);
|
||||||
|
return sets;
|
||||||
|
}
|
||||||
|
|
||||||
|
// return a partition of the given elements {keys}
|
||||||
|
std::map<KEY, Set> partition(const std::list<KEY>& keys) const {
|
||||||
|
std::map<KEY, Set> partitions;
|
||||||
|
BOOST_FOREACH(const KEY& key, keys)
|
||||||
|
partitions[findSet(key)].insert(key);
|
||||||
|
return partitions;
|
||||||
|
}
|
||||||
|
|
||||||
|
// get the nodes in the tree with the given label
|
||||||
|
Set set(const KEY& label) const {
|
||||||
|
Set set;
|
||||||
|
BOOST_FOREACH(const KeyLabel& pair, (Tree)*this) {
|
||||||
|
if (pair.second == label || findSet(pair.second) == label)
|
||||||
|
set.insert(pair.first);
|
||||||
|
}
|
||||||
|
return set;
|
||||||
|
}
|
||||||
|
|
||||||
|
/** equality */
|
||||||
|
bool operator==(const Self& t) const {
|
||||||
|
return (Tree) *this == (Tree) t;
|
||||||
|
}
|
||||||
|
|
||||||
|
/** inequality */
|
||||||
|
bool operator!=(const Self& t) const {
|
||||||
|
return (Tree) *this != (Tree) t;
|
||||||
|
}
|
||||||
|
|
||||||
|
// print the object
|
||||||
|
void print(const std::string& name = "DSF") const {
|
||||||
|
std::cout << name << std::endl;
|
||||||
|
BOOST_FOREACH(const KeyLabel& pair, (Tree)*this)
|
||||||
|
std::cout << (std::string) pair.first << " " << (std::string) pair.second
|
||||||
|
<< std::endl;
|
||||||
|
}
|
||||||
|
|
||||||
|
protected:
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* Disjoint Set Forest class
|
* same as findSet except with path compression: After we have traversed the path to
|
||||||
*
|
* the root, each parent pointer is made to directly point to it
|
||||||
* Quoting from CLR: A disjoint-set data structure maintains a collection
|
|
||||||
* S = {S_1,S_2,...} of disjoint dynamic sets. Each set is identified by
|
|
||||||
* a representative, which is some member of the set.
|
|
||||||
*
|
|
||||||
* @addtogroup base
|
|
||||||
*/
|
*/
|
||||||
template <class KEY>
|
KEY findSet_(const KEY& key) {
|
||||||
class DSF : protected BTree<KEY, KEY> {
|
KEY parent = this->find(key);
|
||||||
|
if (parent == key)
|
||||||
public:
|
return parent;
|
||||||
typedef DSF<KEY> Self;
|
else {
|
||||||
typedef std::set<KEY> Set;
|
KEY label = findSet_(parent);
|
||||||
typedef BTree<KEY, KEY> Tree;
|
*this = this->add(key, label);
|
||||||
typedef std::pair<KEY, KEY> KeyLabel;
|
return label;
|
||||||
|
|
||||||
// constructor
|
|
||||||
DSF() : Tree() { }
|
|
||||||
|
|
||||||
// constructor
|
|
||||||
DSF(const Tree& tree) : Tree(tree) {}
|
|
||||||
|
|
||||||
// constructor with a list of unconnected keys
|
|
||||||
DSF(const std::list<KEY>& keys) : Tree() { BOOST_FOREACH(const KEY& key, keys) *this = this->add(key, key); }
|
|
||||||
|
|
||||||
// constructor with a set of unconnected keys
|
|
||||||
DSF(const std::set<KEY>& keys) : Tree() { BOOST_FOREACH(const KEY& key, keys) *this = this->add(key, key); }
|
|
||||||
|
|
||||||
// create a new singleton, does nothing if already exists
|
|
||||||
Self makeSet(const KEY& key) const { if (this->mem(key)) return *this; else return this->add(key, key); }
|
|
||||||
|
|
||||||
// find the label of the set in which {key} lives
|
|
||||||
KEY findSet(const KEY& key) const {
|
|
||||||
KEY parent = this->find(key);
|
|
||||||
return parent == key ? key : findSet(parent); }
|
|
||||||
|
|
||||||
// return a ***new*** DSF where x and y are in the same set. No path compression
|
|
||||||
Self makeUnion(const KEY& key1, const KEY& key2) const { return this->add(findSet(key2), findSet(key1)); }
|
|
||||||
|
|
||||||
// the in-place version of makeUnion
|
|
||||||
void makeUnionInPlace(const KEY& key1, const KEY& key2) { *this = this->add(findSet_(key2), findSet_(key1)); }
|
|
||||||
|
|
||||||
// create a new singleton with two connected keys
|
|
||||||
Self makePair(const KEY& key1, const KEY& key2) const { return makeSet(key1).makeSet(key2).makeUnion(key1, key2); }
|
|
||||||
|
|
||||||
// create a new singleton with a list of fully connected keys
|
|
||||||
Self makeList(const std::list<KEY>& keys) const {
|
|
||||||
Self t = *this;
|
|
||||||
BOOST_FOREACH(const KEY& key, keys)
|
|
||||||
t = t.makePair(key, keys.front());
|
|
||||||
return t;
|
|
||||||
}
|
}
|
||||||
|
}
|
||||||
|
|
||||||
// return a dsf in which all find_set operations will be O(1) due to path compression.
|
};
|
||||||
DSF flatten() const {
|
|
||||||
DSF t = *this;
|
|
||||||
BOOST_FOREACH(const KeyLabel& pair, (Tree)t)
|
|
||||||
t.findSet_(pair.first);
|
|
||||||
return t;
|
|
||||||
}
|
|
||||||
|
|
||||||
// maps f over all keys, must be invertible
|
// shortcuts
|
||||||
DSF map(boost::function<KEY(const KEY&)> func) const {
|
typedef DSF<int> DSFInt;
|
||||||
DSF t;
|
|
||||||
BOOST_FOREACH(const KeyLabel& pair, (Tree)*this)
|
|
||||||
t = t.add(func(pair.first), func(pair.second));
|
|
||||||
return t;
|
|
||||||
}
|
|
||||||
|
|
||||||
// return the number of sets
|
|
||||||
size_t numSets() const {
|
|
||||||
size_t num = 0;
|
|
||||||
BOOST_FOREACH(const KeyLabel& pair, (Tree)*this)
|
|
||||||
if (pair.first == pair.second) num++;
|
|
||||||
return num;
|
|
||||||
}
|
|
||||||
|
|
||||||
// return the numer of keys
|
|
||||||
size_t size() const { return Tree::size(); }
|
|
||||||
|
|
||||||
// return all sets, i.e. a partition of all elements
|
|
||||||
std::map<KEY, Set> sets() const {
|
|
||||||
std::map<KEY, Set> sets;
|
|
||||||
BOOST_FOREACH(const KeyLabel& pair, (Tree)*this)
|
|
||||||
sets[findSet(pair.second)].insert(pair.first);
|
|
||||||
return sets;
|
|
||||||
}
|
|
||||||
|
|
||||||
// return a partition of the given elements {keys}
|
|
||||||
std::map<KEY, Set> partition(const std::list<KEY>& keys) const {
|
|
||||||
std::map<KEY, Set> partitions;
|
|
||||||
BOOST_FOREACH(const KEY& key, keys)
|
|
||||||
partitions[findSet(key)].insert(key);
|
|
||||||
return partitions;
|
|
||||||
}
|
|
||||||
|
|
||||||
// get the nodes in the tree with the given label
|
|
||||||
Set set(const KEY& label) const {
|
|
||||||
Set set;
|
|
||||||
BOOST_FOREACH(const KeyLabel& pair, (Tree)*this) {
|
|
||||||
if (pair.second == label || findSet(pair.second) == label)
|
|
||||||
set.insert(pair.first);
|
|
||||||
}
|
|
||||||
return set;
|
|
||||||
}
|
|
||||||
|
|
||||||
/** equality */
|
|
||||||
bool operator==(const Self& t) const { return (Tree)*this == (Tree)t; }
|
|
||||||
|
|
||||||
/** inequality */
|
|
||||||
bool operator!=(const Self& t) const { return (Tree)*this != (Tree)t; }
|
|
||||||
|
|
||||||
// print the object
|
|
||||||
void print(const std::string& name = "DSF") const {
|
|
||||||
std::cout << name << std::endl;
|
|
||||||
BOOST_FOREACH(const KeyLabel& pair, (Tree)*this)
|
|
||||||
std::cout << (std::string)pair.first << " " << (std::string)pair.second << std::endl;
|
|
||||||
}
|
|
||||||
|
|
||||||
protected:
|
|
||||||
|
|
||||||
/**
|
|
||||||
* same as findSet except with path compression: After we have traversed the path to
|
|
||||||
* the root, each parent pointer is made to directly point to it
|
|
||||||
*/
|
|
||||||
KEY findSet_(const KEY& key) {
|
|
||||||
KEY parent = this->find(key);
|
|
||||||
if (parent == key)
|
|
||||||
return parent;
|
|
||||||
else {
|
|
||||||
KEY label = findSet_(parent);
|
|
||||||
*this = this->add(key, label);
|
|
||||||
return label;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
};
|
|
||||||
|
|
||||||
// shortcuts
|
|
||||||
typedef DSF<int> DSFInt;
|
|
||||||
|
|
||||||
} // namespace gtsam
|
} // namespace gtsam
|
||||||
|
|
|
||||||
Loading…
Reference in New Issue