/usr/include/sdsl/suffix_array_algorithm.hpp is in libsdsl-dev 2.0.3-4.
This file is owned by root:root, with mode 0o644.
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Copyright (C) 2010-2013 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 suffix_array_algorithm.hpp
\brief suffix_array_algorithm.hpp contains algorithms on CSAs
\author Simon Gog
*/
#ifndef INCLUDED_SDSL_SUFFIX_ARRAY_ALGORITHM
#define INCLUDED_SDSL_SUFFIX_ARRAY_ALGORITHM
#include <iterator>
#include "suffix_array_helper.hpp"
namespace sdsl
{
//! Backward search for a character c in an \f$\omega\f$-interval \f$[\ell..r]\f$ in the CSA.
/*!
* \tparam t_csa CSA type.
*
* \param csa The CSA object.
* \param l Left border of the interval \f$ [\ell..r]\f$.
* \param r Right border of the interval \f$ [\ell..r]\f$.
* \param c Character to be prepended to \f$\omega\f$.
* \param l_res New left border.
* \param r_res Right border.
* \return The size of the new interval [\ell_{new}..r_{new}].
* Equals zero, if no match is found.
*
* \pre \f$ 0 \leq \ell \leq r < csa.size() \f$
*
* \par Time complexity
* \f$ \Order{ t_{rank\_bwt} } \f$
* \par Reference
* Paolo Ferragina, Giovanni Manzini:
* Opportunistic Data Structures with Applications.
* FOCS 2000: 390-398
*/
template<class t_csa>
typename t_csa::size_type backward_search(
const t_csa& csa,
typename t_csa::size_type l,
typename t_csa::size_type r,
typename t_csa::char_type c,
typename t_csa::size_type& l_res,
typename t_csa::size_type& r_res,
SDSL_UNUSED typename std::enable_if<std::is_same<csa_tag, typename t_csa::index_category>::value, csa_tag>::type x = csa_tag()
)
{
assert(l <= r); assert(r < csa.size());
typename t_csa::size_type c_begin = csa.C[csa.char2comp[c]];
l_res = c_begin + csa.bwt.rank(l, c); // count c in bwt[0..l-1]
r_res = c_begin + csa.bwt.rank(r+1, c) - 1; // count c in bwt[0..r]
assert(r_res+1-l_res >= 0);
return r_res+1-l_res;
}
//! Backward search for a pattern in an \f$\omega\f$-interval \f$[\ell..r]\f$ in the CSA.
/*!
* \tparam t_csa A CSA type.
* \tparam t_pat_iter Pattern iterator type.
*
* \param csa The CSA object.
* \param l Left border of the lcp-interval \f$ [\ell..r]\f$.
* \param r Right border of the lcp-interval \f$ [\ell..r]\f$.
* \param begin Iterator to the begin of the pattern (inclusive).
* \param end Iterator to the end of the pattern (exclusive).
* \param l_res New left border.
* \param r_res New right border.
* \return The size of the new interval [\ell_{new}..r_{new}].
* Equals zero, if no match is found.
*
* \pre \f$ 0 \leq \ell \leq r < csa.size() \f$
*
* \par Time complexity
* \f$ \Order{ len \cdot t_{rank\_bwt} } \f$
* \par Reference
* Paolo Ferragina, Giovanni Manzini:
* Opportunistic Data Structures with Applications.
* FOCS 2000: 390-398
*/
template<class t_csa, class t_pat_iter>
typename t_csa::size_type
backward_search(
const t_csa& csa,
typename t_csa::size_type l,
typename t_csa::size_type r,
t_pat_iter begin,
t_pat_iter end,
typename t_csa::size_type& l_res,
typename t_csa::size_type& r_res,
SDSL_UNUSED typename std::enable_if<std::is_same<csa_tag, typename t_csa::index_category>::value, csa_tag>::type x = csa_tag()
)
{
t_pat_iter it = end;
while (begin < it and r+1-l > 0) {
--it;
backward_search(csa, l, r, (typename t_csa::char_type)*it, l, r);
}
l_res = l;
r_res = r;
return r+1-l;
}
//! Bidirectional search for a character c on an interval \f$[l_fwd..r_fwd]\f$ of the suffix array.
/*!
* \param csa_fwd The CSA object of the forward text in which the backward_search should be done.
* \param l_fwd Left border of the lcp-interval \f$ [l_fwd..r_fwd]\f$ in suffix array of the forward text.
* \param r_fwd Right border of the lcp-interval \f$ [l_fwd..r_fwd]\f$ in suffix array of the forward text.
* \param l_bwd Left border of the lcp-interval \f$ [l_bwd..r_bwd]\f$ in suffix array of the backward text.
* \param r_bwd Right border of the lcp-interval \f$ [l_bwd..r_bwd]\f$ in suffix array of the backward text.
* \param c The character c which is the starting character of the suffixes in the resulting interval \f$ [l_fwd_res..r_fwd_res] \f$ .
* \param l_fwd_res Reference to the resulting left border in suffix array of the forward text.
* \param r_fwd_res Reference to the resulting right border in suffix array of the forward text.
* \param l_bwd_res Reference to the resulting left border in suffix array of the backward text.
* \param r_bwd_res Reference to the resulting right border in suffix array of the backward text.
* \return The size of the new interval [l_fwd_res..r_fwd_res].
* \pre \f$ 0 \leq \ell \leq r_fwd < csa_fwd.size() \f$
* \par Reference
* Thomas Schnattinger, Enno Ohlebusch, Simon Gog:
* Bidirectional search in a string with wavelet trees and bidirectional matching statistics.
* Inf. Comput. 213: 13-22
*/
template<class t_wt, uint32_t t_dens, uint32_t t_inv_dens, class t_sa_sample_strat, class t_isa, class t_alphabet_strat>
typename csa_wt<t_wt>::size_type bidirectional_search(
const csa_wt<t_wt, t_dens, t_inv_dens, t_sa_sample_strat, t_isa, t_alphabet_strat>& csa_fwd,
typename csa_wt<>::size_type l_fwd,
typename csa_wt<>::size_type r_fwd,
typename csa_wt<>::size_type l_bwd,
typename csa_wt<>::size_type r_bwd,
typename csa_wt<>::char_type c,
typename csa_wt<>::size_type& l_fwd_res,
typename csa_wt<>::size_type& r_fwd_res,
typename csa_wt<>::size_type& l_bwd_res,
typename csa_wt<>::size_type& r_bwd_res,
SDSL_UNUSED typename std::enable_if< t_wt::lex_ordered, csa_tag>::type x = csa_tag()
)
{
assert(l_fwd <= r_fwd); assert(r_fwd < csa_fwd.size());
typedef typename csa_wt<t_wt, t_dens, t_inv_dens, t_sa_sample_strat, t_isa, t_alphabet_strat>::size_type size_type;
size_type c_begin = csa_fwd.C[csa_fwd.char2comp[c]];
auto r_s_b = csa_fwd.wavelet_tree.lex_count(l_fwd, r_fwd+1, c);
size_type rank_l = std::get<0>(r_s_b);
size_type s = std::get<1>(r_s_b), b = std::get<2>(r_s_b);
size_type rank_r = r_fwd - l_fwd - s - b + rank_l;
l_fwd_res = c_begin + rank_l;
r_fwd_res = c_begin + rank_r;
assert(r_fwd_res+1 >= l_fwd_res);
l_bwd_res = l_bwd + s;
r_bwd_res = r_bwd - b;
assert(r_bwd_res-l_bwd_res == r_fwd_res-l_fwd_res);
return r_fwd_res+1-l_fwd_res;
}
//! Bidirectional search in backward direction.
/*!
* The function requires a pattern \f$p\f$, an \f$\omega\f$-interval \f$[l_fwd..r_fwd]\f$ in the CSA object
* of the forward text and an \f$\omega^{rev}\f$-interval \f$[l_bwd..r_bwd]\f$ in the CSA object of the backward text.
* The function returns the \f$p\omega\f$-interval in the CSA object of the forward text and
* the \f$\omega^{rev}p^{rev}\f$-interval in the CSA object of the backward text.
*
* \tparam t_pat_iter Pattern iterator type.
*
* \param csa_fwd The CSA object of the forward text.
* \param csa_bwd The CSA object of the backward text.
* \param l_fwd Left border of the lcp-interval \f$ [l_fwd..r_fwd]\f$ in suffix array of the forward text.
* \param r_fwd Right border of the lcp-interval \f$ [l_fwd..r_fwd]\f$ in suffix array of the forward text.
* \param l_bwd Left border of the lcp-interval \f$ [l_bwd..r_bwd]\f$ in suffix array of the backward text.
* \param r_bwd Right border of the lcp-interval \f$ [l_bwd..r_bwd]\f$ in suffix array of the backward text.
* \param begin Iterator to the begin of the pattern (inclusive).
* \param end Iterator to the end of the pattern (exclusive).
* \param l_fwd_res Reference to the resulting left border in suffix array of the forward text.
* \param r_fwd_res Reference to the resulting right border in suffix array of the forward text.
* \param l_bwd_res Reference to the resulting left border in suffix array of the backward text.
* \param r_bwd_res Reference to the resulting right border in suffix array of the backward text.
* \return The size of the new interval [l_fwd_res..r_fwd_res].
* Equals zero, if no match is found.
*
* \pre \f$ 0 \leq \ell \leq r_fwd < csa_fwd.size() \f$
* \par Reference
* Thomas Schnattinger, Enno Ohlebusch, Simon Gog:
* Bidirectional search in a string with wavelet trees and bidirectional matching statistics.
* Inf. Comput. 213: 13-22
*/
template<class t_pat_iter, class t_wt, uint32_t t_dens, uint32_t t_inv_dens, class t_sa_sample_strat, class t_isa, class t_alphabet_strat>
typename csa_wt<>::size_type bidirectional_search_backward(
const csa_wt<t_wt, t_dens, t_inv_dens, t_sa_sample_strat, t_isa, t_alphabet_strat>& csa_fwd,
SDSL_UNUSED const csa_wt<t_wt, t_dens, t_inv_dens, t_sa_sample_strat, t_isa, t_alphabet_strat>& csa_bwd,
typename csa_wt<>::size_type l_fwd,
typename csa_wt<>::size_type r_fwd,
typename csa_wt<>::size_type l_bwd,
typename csa_wt<>::size_type r_bwd,
t_pat_iter begin,
t_pat_iter end,
typename csa_wt<>::size_type& l_fwd_res,
typename csa_wt<>::size_type& r_fwd_res,
typename csa_wt<>::size_type& l_bwd_res,
typename csa_wt<>::size_type& r_bwd_res,
SDSL_UNUSED typename std::enable_if< t_wt::lex_ordered, csa_tag>::type x = csa_tag()
)
{
t_pat_iter it = end;
while (begin < it and r_fwd+1-l_fwd > 0) {
--it;
bidirectional_search(csa_fwd, l_fwd, r_fwd, l_bwd, r_bwd, (typename csa_wt<>::char_type)*it, l_fwd, r_fwd, l_bwd, r_bwd);
}
l_fwd_res = l_fwd;
r_fwd_res = r_fwd;
l_bwd_res = l_bwd;
r_bwd_res = r_bwd;
return r_fwd+1-l_fwd;
}
//! Bidirectional search in forward direction.
/*!
* The function requires a pattern \f$p\f$, an \f$\omega\f$-interval \f$[l_fwd..r_fwd]\f$ in the CSA object
* of the forward text and an \f$\omega^{rev}\f$-interval \f$[l_bwd..r_bwd]\f$ in the CSA object of the backward text.
* The function returns the \f$\omega p\f$-interval in the CSA object of the forward text and
* the \f$\p^{rev}omega^{rev}\f$-interval in the CSA object of the backward text.
*
* \tparam t_pat_iter Pattern iterator type.
*
* \param csa_fwd The CSA object of the forward text.
* \param csa_bwd The CSA object of the backward text.
* \param l_fwd Left border of the lcp-interval \f$ [l_fwd..r_fwd]\f$ in suffix array of the forward text.
* \param r_fwd Right border of the lcp-interval \f$ [l_fwd..r_fwd]\f$ in suffix array of the forward text.
* \param l_bwd Left border of the lcp-interval \f$ [l_bwd..r_bwd]\f$ in suffix array of the backward text.
* \param r_bwd Right border of the lcp-interval \f$ [l_bwd..r_bwd]\f$ in suffix array of the backward text.
* \param begin Iterator to the begin of the pattern (inclusive).
* \param end Iterator to the end of the pattern (exclusive).
* \param l_fwd_res Reference to the resulting left border in suffix array of the forward text.
* \param r_fwd_res Reference to the resulting right border in suffix array of the forward text.
* \param l_bwd_res Reference to the resulting left border in suffix array of the backward text.
* \param r_bwd_res Reference to the resulting right border in suffix array of the backward text.
* \return The size of the new interval [l_fwd_res..r_fwd_res].
* Equals zero, if no match is found.
*
* \pre \f$ 0 \leq \ell \leq r_fwd < csa_fwd.size() \f$
* \par Reference
* Thomas Schnattinger, Enno Ohlebusch, Simon Gog:
* Bidirectional search in a string with wavelet trees and bidirectional matching statistics.
* Inf. Comput. 213: 13-22
*/
template<class t_pat_iter,
class t_wt,
uint32_t t_dens,
uint32_t t_inv_dens,
class t_sa_sample_strat,
class t_isa,
class t_alphabet_strat>
typename csa_wt<t_wt>::size_type
bidirectional_search_forward(
SDSL_UNUSED const csa_wt<t_wt, t_dens, t_inv_dens, t_sa_sample_strat, t_isa, t_alphabet_strat>& csa_fwd,
const csa_wt<t_wt, t_dens, t_inv_dens, t_sa_sample_strat, t_isa, t_alphabet_strat>& csa_bwd,
typename csa_wt<>::size_type l_fwd,
typename csa_wt<>::size_type r_fwd,
typename csa_wt<>::size_type l_bwd,
typename csa_wt<>::size_type r_bwd,
t_pat_iter begin,
t_pat_iter end,
typename csa_wt<>::size_type& l_fwd_res,
typename csa_wt<>::size_type& r_fwd_res,
typename csa_wt<>::size_type& l_bwd_res,
typename csa_wt<>::size_type& r_bwd_res,
SDSL_UNUSED typename std::enable_if< t_wt::lex_ordered, csa_tag>::type x = csa_tag()
)
{
t_pat_iter it = begin;
while (it < end and r_fwd+1-l_fwd > 0) {
bidirectional_search(csa_bwd, l_bwd, r_bwd, l_fwd, r_fwd, (typename csa_wt<>::char_type)*it, l_bwd, r_bwd, l_fwd, r_fwd);
++it;
}
l_fwd_res = l_fwd;
r_fwd_res = r_fwd;
l_bwd_res = l_bwd;
r_bwd_res = r_bwd;
return r_fwd+1-l_fwd;
}
//! Counts the number of occurrences of a pattern in a CSA.
/*!
* \tparam t_csa CSA type.
* \tparam t_pat_iter Pattern iterator type.
*
* \param csa The CSA object.
* \param begin Iterator to the begin of the pattern (inclusive).
* \param end Iterator to the end of the pattern (exclusive).
* \return The number of occurrences of the pattern in the CSA.
*
* \par Time complexity
* \f$ \Order{ t_{backward\_search} } \f$
*/
template<class t_csa, class t_pat_iter>
typename t_csa::size_type count(
const t_csa& csa,
t_pat_iter begin,
t_pat_iter end,
csa_tag
)
{
if (end - begin > (typename std::iterator_traits<t_pat_iter>::difference_type)csa.size())
return 0;
typename t_csa::size_type t=0; // dummy variable for the backward_search call
typename t_csa::size_type result = backward_search(csa, 0, csa.size()-1, begin, end, t, t);
return result;
}
template<class t_csx, class t_pat_iter>
typename t_csx::size_type count(
const t_csx& csx,
t_pat_iter begin,
t_pat_iter end
)
{
typename t_csx::index_category tag;
return count(csx, begin, end, tag);
}
//! Counts the number of occurrences of a pattern in a CSA.
/*!
* \tparam t_csa CSA type.
*
* \param csa The CSA object.
* \param pat The pattern.
* \return The number of occurrences of the pattern in the CSA.
*
* \par Time complexity
* \f$ \Order{ t_{backward\_search} } \f$
*/
template<class t_csx>
typename t_csx::size_type count(
const t_csx& csx,
const typename t_csx::string_type& pat
)
{
typename t_csx::index_category tag;
return count(csx, pat.begin(), pat.end(), tag);
}
//! Calculates all occurrences of a pattern pat in a CSA.
/*!
* \tparam t_csa CSA type.
* \tparam t_pat_iter Pattern iterator type.
* \tparam t_rac Resizeable random access container.
*
* \param csa The CSA object.
* \param begin Iterator to the begin of the pattern (inclusive).
* \param end Iterator to the end of the pattern (exclusive).
* \return A vector containing the occurrences of the pattern in the CSA.
*
* \par Time complexity
* \f$ \Order{ t_{backward\_search} + z \cdot t_{SA} } \f$, where \f$z\f$ is the number of
* occurrences of pattern in the CSA.
*/
template<class t_csa, class t_pat_iter, class t_rac=int_vector<64>>
t_rac locate(
const t_csa& csa,
t_pat_iter begin,
t_pat_iter end,
SDSL_UNUSED typename std::enable_if<std::is_same<csa_tag, typename t_csa::index_category>::value, csa_tag>::type x = csa_tag()
)
{
typename t_csa::size_type occ_begin, occ_end, occs;
occs = backward_search(csa, 0, csa.size()-1, begin, end, occ_begin, occ_end);
t_rac occ(occs);
for (typename t_csa::size_type i=0; i < occs; ++i) {
occ[i] = csa[occ_begin+i];
}
return occ;
}
//! Calculates all occurrences of a pattern pat in a CSA/CST.
/*!
* \tparam t_csa CSA/CST type.
* \tparam t_rac Resizeable random access container.
*
* \param csa The CSA/CST object.
* \param pat The pattern.
* \return A vector containing the occurrences of the pattern in the CSA.
*
* \par Time complexity
* \f$ \Order{ t_{backward\_search} + z \cdot t_{SA} } \f$, where \f$z\f$ is the number of
* occurrences of pattern in the CSA.
*/
template<class t_csx, class t_rac=int_vector<64>>
t_rac locate(
const t_csx& csx,
const typename t_csx::string_type& pat
)
{
typename t_csx::index_category tag;
return locate<t_csx, decltype(pat.begin()), t_rac>(csx, pat.begin(), pat.end(), tag);
}
//! Writes the substring T[begin..end] of the original text T to text[0..end-begin+1].
/*!
* \tparam t_csa CSA type.
* \tparam t_text_iter Random access iterator type.
*
* \param csa The CSA object.
* \param begin Position of the first character which should be extracted (inclusive).
* \param end Position of the last character which should be extracted (inclusive).
* \param text Random access iterator pointing to the start of an container, which can hold at least (end-begin+1) character.
* \returns The length of the extracted text.
* \pre \f$begin <= end\f$ and \f$ end < csa.size() \f$
* \par Time complexity
* \f$ \Order{ (end-begin+1) \cdot t_{\Psi} + t_{SA^{-1}} } \f$
*/
template<class t_csa, class t_text_iter>
typename t_csa::size_type extract(
const t_csa& csa,
typename t_csa::size_type begin,
typename t_csa::size_type end,
t_text_iter text,
SDSL_UNUSED typename std::enable_if<std::is_same<csa_tag, typename t_csa::index_category>::value, csa_tag>::type x = csa_tag()
)
{
typename t_csa::extract_category extract_tag;
return extract(csa, begin, end, text, extract_tag);
}
//! Specialization of extract for LF-function based CSAs
template<class t_csa, class t_text_iter>
typename t_csa::size_type extract(
const t_csa& csa,
typename t_csa::size_type begin,
typename t_csa::size_type end,
t_text_iter text,
lf_tag
)
{
assert(end < csa.size());
assert(begin <= end);
auto steps = end-begin+1;
if (steps > 0) {
auto order = csa.isa[end];
text[--steps] = first_row_symbol(order, csa);
while (steps != 0) {
auto rc = csa.wavelet_tree.inverse_select(order);
auto j = rc.first;
auto c = rc.second;
order = csa.C[ csa.char2comp[c] ] + j;
text[--steps] = c;
}
}
return end-begin+1;
}
//! Specialization of extract for \f$\Psi\f$-function based CSAs
template<class t_csa, class t_text_iter>
typename t_csa::size_type extract(
const t_csa& csa,
typename t_csa::size_type begin,
typename t_csa::size_type end,
t_text_iter text,
psi_tag
)
{
assert(end < csa.size());
assert(begin <= end);
typename t_csa::size_type steps = end-begin+1;
for (typename t_csa::size_type i=0, order = csa.isa[begin]; steps != 0; --steps, ++i) {
text[i] = first_row_symbol(order, csa);
if (steps != 0) order = csa.psi[order];
}
return end-begin+1;
}
//! Reconstructs the substring T[begin..end] of the original text T to text[0..end-begin+1].
/*!
* \tparam t_rac Random access container which should hold the result.
* \tparam t_csa CSA type.
*
* \param csa The CSA object.
* \param begin Position of the first character which should be extracted (inclusive).
* \param end Position of the last character which should be extracted (inclusive).
* \return A t_rac object holding the extracted text.
* \pre \f$begin <= end\f$ and \f$ end < csa.size() \f$
* \par Time complexity
* \f$ \Order{ (end-begin+1) \cdot t_{\Psi} + t_{SA^{-1}} } \f$
*/
template<class t_csa>
typename t_csa::string_type extract(
const t_csa& csa,
typename t_csa::size_type begin,
typename t_csa::size_type end,
SDSL_UNUSED typename std::enable_if<std::is_same<csa_tag, typename t_csa::index_category>::value, csa_tag>::type x = csa_tag()
)
{
assert(end <= csa.size());
assert(begin <= end);
typedef typename t_csa::string_type string_type;
string_type result(end-begin+1, (typename string_type::value_type)0);
extract(csa, begin, end, result.begin());
return result;
}
} // end namespace
#endif
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