algo: covers: Extract common function isBorder

alib2algo/src/stringology/cover/ApproximateEnhancedCoversCommon.h

@@ -159,6 +159,22 @@ protected:
 		return nextState;
 	}
+	/**
+	 * Checks if a string represented by the state of the
+	 * k-approximate deterministic suffix automaton is an exact border.
+	 *
+	 * @param state
+	 * @param x the original string
+	 * @param k maximum number of allowed errors
+	 * @return true if state represents border, false otherwise
+	 */
+	template < class SymbolType >
+	static bool isBorder ( const State & state, const string::LinearString < SymbolType > & x, unsigned k ) {
+		Element lastElement = state.elements[state.elements.size ( ) - 1];
+
+		return ( state.elements[0].depth == state.depth && lastElement.depth == x.getContent ( ).size ( ) ) && ( lastElement.level == 0 ) && ( state.depth > k );
+	}
+
 	/**
 	 * Makes actual set of (relaxed) approximate enhanced covers from the set of
 	 * lfactors, so the set of pairs of end position of factor and length of

alib2algo/src/stringology/cover/ApproximateEnhancedCoversComputation.h

@@ -19,19 +19,6 @@ public:
 	 */
 	template < class SymbolType >
 	static ext::set < string::LinearString < SymbolType > > compute ( const string::LinearString < SymbolType > & x, unsigned k );
-
-private:
-	/**
-	 * Checks if a string represented by the state of the backbone of
-	 * k-approximate deterministic suffix automaton is a border.
-	 *
-	 * @param state
-	 * @param x the original string
-	 * @param k maximum number of allowed errors
-	 * @return true if state represents border, false otherwise
-	 */
-	template < class SymbolType >
-	static bool isBorder ( const State & state, const string::LinearString < SymbolType > & x, unsigned k );
 };
 template < class SymbolType >
@@ -70,12 +57,5 @@ ext::set < string::LinearString < SymbolType > > ApproximateEnhancedCoversComput
 	return getFactors ( x, result );
 }
-template < class SymbolType >
-bool ApproximateEnhancedCoversComputation::isBorder ( const State & state, const string::LinearString < SymbolType > & x, unsigned k ) {
-	Element lastElement = state.elements[state.elements.size ( ) - 1];
-
-	return ( lastElement.depth == x.getContent ( ).size ( ) ) && ( lastElement.level == 0 ) && ( state.depth > k );
-}
-
 } /* namespace stringology::cover */
 #endif /* APPROXIMATE_ENHANCED_COVERS_COMPUTATION_H */

alib2algo/src/stringology/cover/RelaxedApproximateEnhancedCoversComputation.h

@@ -60,7 +60,7 @@ ext::set < string::LinearString < SymbolType > > RelaxedApproximateEnhancedCover
 		State firstState = constrFirstState ( x, k, symbol );
 		 // check if the first character is a border (makes sense only for k = 0)
-		if ( ( firstState.elements[0].depth == 1 ) && ( firstState.elements[firstState.elements.size ( ) - 1].depth == x.getContent ( ).size ( ) ) && ( k == 0 ) )
+		if ( isBorder ( firstState, x, k ) )
 			updateEnhCov ( firstState, result, h );
 		processState ( x, k, firstState, result, h );