add Nyldon factoring algorithm

alib2algo/src/stringology/properties/NyldonFactoring.cpp

+/*
+ * NyldonFactoring.cpp
+ *
+ *  Created on: 30. 8. 2018
+ *      Author: Jan Travnicek
+ */
+
+#include "NyldonFactoring.h"
+#include <registration/AlgoRegistration.hpp>
+
+namespace {
+
+auto nyldonFactoringString = registration::AbstractRegister < stringology::properties::NyldonFactoring, ext::vector < unsigned >, const string::LinearString < > & > ( stringology::properties::NyldonFactoring::factorize ).setDocumentation (
+"Computes the nyldon factoring of a given nonempty string\n\
+\n\
+@param string the nonempty string to factorize\n\
+@return positions where the string is split to nyldon factors" );
+
+} /* namespace */

alib2algo/src/stringology/properties/NyldonFactoring.h

+/*
+ * NyldonFactoring.h
+ *
+ *  Created on: 29. 8. 2019
+ *      Author: Jan Travnicek
+ *
+ * Based on code from arXiv:1804.09735
+ */
+
+#ifndef NYLDON_FACTORING_H_
+#define NYLDON_FACTORING_H_
+
+#include <string/LinearString.h>
+
+#include <alib/deque>
+
+namespace stringology {
+
+namespace properties {
+
+class NyldonFactoring {
+public:
+	/**
+	 * Computes the nyldon factoring of a given nonempty string.
+	 *
+	 * @param string the nonempty string to factorize
+	 * @return positions where the string is split to nyldon factors
+	 */
+	template < class SymbolType >
+	static ext::vector < unsigned > factorize ( const string::LinearString < SymbolType > & string );
+
+};
+
+template < class SymbolType >
+ext::vector < unsigned > NyldonFactoring::factorize ( const string::LinearString < SymbolType > & string ) {
+	unsigned n = string.getContent ( ).size ( );
+	ext::deque < ext::vector < SymbolType > > NyIF { ext::vector < SymbolType > { string.getContent ( ) [ n - 1 ] } };
+	for ( unsigned i = 2; i <= n; ++ i ) {
+		NyIF.push_front ( ext::vector < SymbolType > { string.getContent ( ) [ n - i ] } );
+		while ( NyIF.size ( ) >= 2 && NyIF [ 0 ] > NyIF [ 1 ] ) {
+			ext::vector < SymbolType > tmp = std::move ( NyIF [ 0 ] );
+			tmp.insert ( tmp.end ( ), NyIF [ 1 ].begin ( ), NyIF [ 1 ].end ( ) );
+
+			NyIF.pop_front ( );
+			NyIF.pop_front ( );
+			NyIF.push_front ( std::move ( tmp ) );
+		}
+	}
+
+	ext::vector < unsigned > factorization;
+	unsigned i = 0;
+	for ( const ext::vector < SymbolType > factor : NyIF ) {
+		factorization.push_back ( i );
+		i += factor.size ( );
+	}
+	return factorization;
+}
+
+} /* namespace properties */
+
+} /* namespace stringology */
+
+#endif /* NYLDON_FACTORING_H_ */