From 2dda6f1e978f5834f69059358ad1eaa5b3f85092 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Tr=C3=A1vn=C3=AD=C4=8Dek?= <jan.travnicek@fit.cvut.cz>
Date: Sun, 30 Jan 2022 10:59:24 +0100
Subject: [PATCH] algo: factor out common function from two stringology algos
---
.../src/stringology/common/CommonAlgorithm.h | 9 +++++++++
alib2algo/src/stringology/exact/GalilSeiferas.h | 16 +++++++---------
.../src/stringology/exact/SequentialSampling.h | 14 ++++++--------
3 files changed, 22 insertions(+), 17 deletions(-)
create mode 100644 alib2algo/src/stringology/common/CommonAlgorithm.h
diff --git a/alib2algo/src/stringology/common/CommonAlgorithm.h b/alib2algo/src/stringology/common/CommonAlgorithm.h
new file mode 100644
index 0000000000..a1e2279b76
--- /dev/null
+++ b/alib2algo/src/stringology/common/CommonAlgorithm.h
@@ -0,0 +1,9 @@
+#pragma once
+
+namespace stringology::common {
+
+inline size_t div_up ( size_t x, size_t y ) {
+ return x / y + ( x % y == 1 );
+}
+
+} /* namespace stringology::common */
diff --git a/alib2algo/src/stringology/exact/GalilSeiferas.h b/alib2algo/src/stringology/exact/GalilSeiferas.h
index cbf5b84710..76650d61e5 100644
--- a/alib2algo/src/stringology/exact/GalilSeiferas.h
+++ b/alib2algo/src/stringology/exact/GalilSeiferas.h
@@ -10,6 +10,8 @@
#include <common/createUnique.hpp>
#include <alphabet/EndSymbol.h>
+#include <stringology/common/CommonAlgorithm.h>
+
namespace stringology::exact {
/**
@@ -17,10 +19,6 @@ namespace stringology::exact {
* Zvi Galil and Joel Seiferas
*/
class GalilSeiferas{
- static size_t div_up ( size_t x, size_t y ) {
- return ( x % y == 1 ) ? x / y + 1 : x / y;
- }
-
public:
/**
* Search for pattern in linear string.
@@ -35,7 +33,7 @@ ext::set < unsigned > GalilSeiferas::match ( const string::LinearString < Symbol
ext::set < unsigned > occ;
// add terminating symbol to subject
- SymbolType endSymbol = common::createUnique ( alphabet::EndSymbol::instance < SymbolType > ( ), subject.getAlphabet ( ), pattern.getAlphabet ( ) );
+ SymbolType endSymbol = ::common::createUnique ( alphabet::EndSymbol::instance < SymbolType > ( ), subject.getAlphabet ( ), pattern.getAlphabet ( ) );
ext::vector < SymbolType > extendedSubject = subject.getContent ( );
extendedSubject.push_back ( endSymbol );
@@ -67,7 +65,7 @@ newp1:
if ( s + p1 + q1 == m )
goto search;
- p1 += std::max( static_cast < size_t > ( 1 ) , div_up ( q1 , k ) );
+ p1 += std::max( static_cast < size_t > ( 1 ) , common::div_up ( q1 , k ) );
q1 = 0;
goto newp1;
@@ -82,7 +80,7 @@ newp2:
p2 += p1;
q2 -= p1;
} else {
- p2 += std::max ( static_cast < size_t > ( 1 ) , div_up(q2 , k));
+ p2 += std::max ( static_cast < size_t > ( 1 ) , common::div_up(q2 , k));
q2 = 0;
}
goto newp2;
@@ -94,7 +92,7 @@ parse:
s += p1;
q1 -= p1;
}
- p1 += std::max ( static_cast < size_t > ( 1 ) , div_up(q1 , k ));
+ p1 += std::max ( static_cast < size_t > ( 1 ) , common::div_up(q1 , k ));
q1 = 0;
if ( p1 < p2 )
goto parse;
@@ -111,7 +109,7 @@ search:
p += p1;
q -= p1;
} else {
- p += std::max ( static_cast < size_t > ( 1 ), div_up(q, k));
+ p += std::max ( static_cast < size_t > ( 1 ), common::div_up(q, k));
q = 0;
}
}
diff --git a/alib2algo/src/stringology/exact/SequentialSampling.h b/alib2algo/src/stringology/exact/SequentialSampling.h
index cc9daa6b69..558e6b79db 100644
--- a/alib2algo/src/stringology/exact/SequentialSampling.h
+++ b/alib2algo/src/stringology/exact/SequentialSampling.h
@@ -5,6 +5,8 @@
#include <alib/set>
#include <alib/vector>
+#include <stringology/common/CommonAlgorithm.h>
+
#include <string/properties/PeriodicPrefix.h>
#include <string/LinearString.h>
@@ -12,10 +14,6 @@ namespace stringology::exact {
namespace {
-inline size_t div_up ( size_t x, size_t y ) {
- return ( x % y == 1 ) ? x / y + 1 : x / y;
-}
-
template <class SymbolType>
ext::set < unsigned > SimpleTextSearching ( const string::LinearString < SymbolType > & subject, const string::LinearString < SymbolType > & pattern ) {
ext::set<unsigned> occ;
@@ -33,7 +31,7 @@ ext::set < unsigned > SimpleTextSearching ( const string::LinearString < SymbolT
if ( j == m )
occ.insert(i);
- i += div_up( j + 1, 2 );
+ i += common::div_up( j + 1, 2 );
}
return occ;
}
@@ -53,7 +51,7 @@ size_t SimpleTextSearchingFirst ( const ext::vector< SymbolType > & text, const
if ( j == m )
return i;
- i += div_up( j + 1, 2 );
+ i += common::div_up( j + 1, 2 );
}
return n;
}
@@ -80,7 +78,7 @@ ext::set < unsigned > SeqSampling ( const string::LinearString < SymbolType > &
if ( j + 1 < q )
i += p;
else
- i += div_up ( j + 1, 2 );
+ i += common::div_up ( j + 1, 2 );
}
}
return occ;
@@ -106,7 +104,7 @@ size_t SeqSamplingFirst ( const ext::vector< SymbolType > & text, const ext::vec
if ( j < q - 1 )
i += p;
else
- i += div_up ( j + 1, 2 );
+ i += common::div_up ( j + 1, 2 );
}
}
return n;
--
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