/usr/include/sdsl/sorted_stack_support.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 | /* sdsl - succinct data structures library
Copyright (C) 2009 Simon Gog
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see http://www.gnu.org/licenses/ .
*/
/*! \file sorted_stack_support.hpp
\author Simon Gog
*/
#ifndef INCLUDED_SDSL_SORTED_STACK_SUPPORT
#define INCLUDED_SDSL_SORTED_STACK_SUPPORT
#include "int_vector.hpp"
namespace sdsl
{
//! A stack which contains strictly increasing pointer to strictly increasing elements in an array.
/*!
* \par Reference
* Johannes Fischer:
* Optimal Succinctness for Range Minimum Queries
* LATIN 2010
*
* \par Space complexity
* \f$n\f$ bits
*/
class sorted_stack_support
{
public:
typedef int_vector<64>::size_type size_type;
private:
size_type m_n; // Size of the supported vector.
size_type m_cnt; // Counter for the indices on the stack.
size_type m_top; // Topmost index of the stack.
int_vector<64> m_stack; // Memory for the stack.
inline size_type block_nr(size_type x) {
return x/63;
}; // TODO: maybe we can speed this up with bit hacks
inline size_type block_pos(size_type x) {
return x%63;
}; // TODO: maybe we can speed this up with bit hacks
public:
//! Constructor
/*! \param n Maximum that can be pushed onto the stack
*/
sorted_stack_support(size_type n);
sorted_stack_support(const sorted_stack_support&) = default;
sorted_stack_support(sorted_stack_support&&) = default;
sorted_stack_support& operator=(const sorted_stack_support&) = default;
sorted_stack_support& operator=(sorted_stack_support&&) = default;
/*! Returns if the stack is empty.
*/
bool empty() const {
return 0==m_cnt;
};
/*! Returns the topmost index on the stack.
* \pre empty()==false
*/
size_type top() const;
/*! Pop the topmost index of the stack.
*/
void pop();
/*! Push the index x of vector vec onto the stack.
* \par x Index of the value in vec which should be pushed onto the stack.
* \pre top() < x
*/
void push(size_type x);
/*! Returns the number of element is the stack.
*/
size_type size()const {
return m_cnt;
};
size_type
serialize(std::ostream& out, structure_tree_node* v=nullptr,
std::string name="")const;
void load(std::istream& in);
};
inline sorted_stack_support::sorted_stack_support(size_type n):m_n(n), m_cnt(0), m_top(0), m_stack()
{
m_stack = int_vector<64>(block_nr(m_n+1)+1, 0);
m_stack[0] = 1;
}
inline sorted_stack_support::size_type sorted_stack_support::top()const
{
return m_top-1;
}
inline void sorted_stack_support::push(size_type x)
{
x += 1;
++m_cnt; //< increment counter
size_type bn = block_nr(x);
m_stack[bn] ^= (1ULL << block_pos(x));
if (bn > 0 and m_stack[bn-1] == 0) {
m_stack[bn-1] = 0x8000000000000000ULL | m_top;
}
m_top = x;
}
inline void sorted_stack_support::pop()
{
if (!empty()) {
--m_cnt; //< decrement counter
size_type bn = block_nr(m_top);
uint64_t w = m_stack[ bn ];
assert((w>>63) == 0); // highest bit is not set, as the block contains no pointer
w ^= (1ULL << block_pos(m_top));
m_stack[ bn ] = w;
if (w>0) {
m_top = bn*63 + bits::hi(w);
} else { // w==0 and cnt>0
assert(bn > 0);
w = m_stack[ bn-1 ];
if ((w>>63) == 0) { // highest bit is not set => the block contains no pointer
assert(w>0);
m_top = (bn-1)*63 + bits::hi(w);
} else { // block contains pointers
m_stack[bn-1] = 0;
m_top = w&0x7FFFFFFFFFFFFFFFULL;
}
}
}
}
inline sorted_stack_support::size_type
sorted_stack_support::serialize(std::ostream& out, structure_tree_node* v,
std::string name)const
{
structure_tree_node* child = structure_tree::add_child(v, name, util::class_name(*this));
size_type written_bytes = 0;
written_bytes += write_member(m_n, out);
written_bytes += write_member(m_top, out);
written_bytes += write_member(m_cnt, out);
written_bytes += m_stack.serialize(out);
structure_tree::add_size(child, written_bytes);
return written_bytes;
}
inline void sorted_stack_support::load(std::istream& in)
{
read_member(m_n, in);
read_member(m_top, in);
read_member(m_cnt, in);
m_stack.load(in);
}
}// end namespace sdsl
#endif // end file
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