/usr/include/sdsl/louds_tree.hpp is in libsdsl-dev 2.0.3-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 | /* sdsl - succinct data structures library
Copyright (C) 2012 Simon Gog
*/
/*! \file louds_tree.hpp
\brief louds_tree.hpp contains a classes for the succinct tree representation LOUDS (level order unary degree sequence).
\author Simon Gog
*/
#ifndef INCLUDED_SDSL_LOUDS_TREE
#define INCLUDED_SDSL_LOUDS_TREE
#include "int_vector.hpp"
#include "util.hpp"
#include <ostream>
//! Namespace for the succinct data structure library.
namespace sdsl
{
//! A class for the node representation of louds_tree
class louds_node
{
public:
typedef bit_vector::size_type size_type;
private:
size_type m_nr; // node number
size_type m_pos; // position in the LOUDS
public:
const size_type& nr;
const size_type& pos;
louds_node(size_type f_nr=0, size_type f_pos=0):m_nr(f_nr), m_pos(f_pos),nr(m_nr),pos(m_pos) {}
bool operator==(const louds_node& v)const {
return m_nr == v.m_nr and m_pos ==v.m_pos;
}
bool operator!=(const louds_node& v)const {
return !(v==*this);
}
};
std::ostream& operator<<(std::ostream& os, const louds_node& v);
//! A tree class based on the level order unary degree sequence (LOUDS) representation.
/*!
* \tparam bit_vec_t The bit vector representation used for LOUDS.
* \tparam select_1_t A select_support on 1-bits required for the child(v,i) operation.
* \tparam select_0_t A select_support on 0-bits required for the parent operation.
*
* Example of the structure: A tree with balanced parentheses representation (()()(()()))
* is translated into 10001110011. Traverse the tree in breadth-first order an write
* for each node a 1-bit followed by as many 0-bits as the node has children.
*
* Disadvantages of louds: No efficient support for subtree size.
*/
template<class bit_vec_t = bit_vector, class select_1_t = typename bit_vec_t::select_1_type, class select_0_t = typename bit_vec_t::select_0_type>
class louds_tree
{
public:
typedef bit_vector::size_type size_type;
typedef louds_node node_type;
typedef bit_vec_t bit_vector_type;
typedef select_1_t select_1_type;
typedef select_0_t select_0_type;
private:
bit_vector_type m_bv; // bit vector for the LOUDS sequence
select_1_type m_bv_select1; // select support for 1-bits on m_bv
select_0_type m_bv_select0; // select support for 0-bits on m_bv
public:
const bit_vector_type& bv; // const reference to the LOUDS sequence
//! Constructor for a cst and a root node for the traversal
template<class Cst, class CstBfsIterator>
louds_tree(const Cst& cst, const CstBfsIterator begin, const CstBfsIterator end):m_bv(), m_bv_select1(), m_bv_select0(), bv(m_bv) {
bit_vector tmp_bv(4*cst.size(*begin) , 0); // resize the bit_vector to the maximal
// possible size 2*2*#leaves in the tree
size_type pos = 0;
for (CstBfsIterator it = begin; it != end;) {
tmp_bv[pos++] = 1;
size_type size = it.size();
++it;
pos += it.size()+1-size;
}
tmp_bv.resize(pos);
m_bv = bit_vector_type(std::move(tmp_bv));
util::init_support(m_bv_select1, &m_bv);
util::init_support(m_bv_select0, &m_bv);
}
louds_tree(const louds_tree& lt) : bv(m_bv) {
*this = lt;
}
louds_tree(louds_tree&& lt) : bv(m_bv) {
*this = std::move(lt);
}
louds_tree& operator=(const louds_tree& lt) {
if (this != <) {
m_bv = lt.m_bv;
m_bv_select1 = lt.m_bv_select1;
m_bv_select1.set_vector(&m_bv);
m_bv_select0 = lt.m_bv_select0;
m_bv_select0.set_vector(&m_bv);
}
return *this;
}
louds_tree& operator=(louds_tree&& lt) {
if (this != <) {
m_bv = std::move(lt.m_bv);
m_bv_select1 = std::move(lt.m_bv_select1);
m_bv_select1.set_vector(&m_bv);
m_bv_select0 = std::move(lt.m_bv_select0);
m_bv_select0.set_vector(&m_bv);
}
return *this;
}
//! Returns the root node
node_type root() const {
return louds_node(0, 0);
}
//! Returns the number of nodes in the tree.
size_type nodes()const {
return m_bv.size()+1/2;
}
//! Indicates if a node is a leaf.
/*! \param v A node.
*/
bool is_leaf(const node_type& v) const {
// node is the last leaf or has no children, so m_bv[v.pos]==1
return (v.pos+1 == m_bv.size()) or m_bv[v.pos+1];
}
//! Returns the number of children of a node.
/*!
* \param v A node.
*/
size_type degree(const node_type& v) const {
if (is_leaf(v)) { // handles boundary cases
return 0;
}
// position of the next node - node position - 1
return m_bv_select1(v.nr+2) - v.pos - 1;
}
//! Returns the i-child of a node.
/*!
* \param v The parent node.
* \param i Index of the child. Indexing starts at 1.
* \pre \f$ i \in [1..degree(v)] \f$
*/
node_type child(const node_type& v, size_type i)const {
size_type pos = v.pos+i; // go to the position of the child's zero
// (#bits = pos+1) - (#1-bits = v.nr+1)
size_type zeros = pos+1 - (v.nr+1);
return louds_node(zeros, m_bv_select1(zeros+1));
}
//! Returns the parent of a node v or root() if v==root().
node_type parent(const node_type& v)const {
if (v == root()) {
return root();
}
size_type zero_pos = m_bv_select0(v.nr);
size_type parent_nr = (zero_pos+1) - v.nr - 1;
return node_type(parent_nr, m_bv_select1(parent_nr+1));
}
//! Returns an unique id for each node in [0..size()-1]
size_type id(const node_type& v)const {
return v.nr;
}
void swap(louds_tree& tree) {
m_bv.swap(tree.m_bv);
util::swap_support(m_bv_select1, tree.m_select1, &m_bv, &(tree.m_bv));
util::swap_support(m_bv_select0, tree.m_select0, &m_bv, &(tree.m_bv));
}
size_type serialize(std::ostream& out, structure_tree_node* v=nullptr, std::string name="")const {
structure_tree_node* child = structure_tree::add_child(v, name, util::class_name(*this));
size_type written_bytes = 0;
m_bv.serialize(out, child, "bitvector");
m_bv_select1(out, child, "select1");
m_bv_select0(out, child, "select0");
structure_tree::add_size(child, written_bytes);
return written_bytes;
}
void load(std::istream& in) {
m_bv.load(in);
m_bv_select1.load(in);
m_bv_select1.set_vector(&m_bv);
m_bv_select0.load(in);
m_bv_select0.set_vector(&m_bv);
}
};
}// end namespace sdsl
#endif
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