Performance improvement for the PatternFiltering

src/main/java/be/uantwerpen/datamining/pattern_mining/PatternUtils.java

@@ -7,6 +7,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Map;
@@ -113,7 +114,6 @@ public class PatternUtils {
 			// new id map IT DOESN'T COVER ALL OF THE IDS ON UP TO THE POINT WHERE THE PATTERNS ARE REMOVED
 			Map<Integer, Integer> newIdMap = new HashMap<>();
 			Collections.sort(toRemove);
-
 			int min = 1;
 			int offset = 0;
 			for(Integer idToRemove : toRemove) {
@@ -134,7 +134,10 @@ public class PatternUtils {
 			File patternOccFile = new File(Settings.FILE_FOLDER + patternSet.getFilenameOccurrences());
 			Table patterOcc = CSVUtils.loadCSV(patternOccFile);
 
-			Iterator<List<String>> occurrencesIterator = patterOcc.getRowsStartingFrom1().iterator();
+
+			//linked lists have way better removing performance than arrays
+			final List<List<String>> occRows = new LinkedList<>(patterOcc.getRowsStartingFrom1());
+			Iterator<List<String>> occurrencesIterator = occRows.iterator();
 			while(occurrencesIterator.hasNext()) {
 				List<String> row = occurrencesIterator.next();
 				final int patternId = Integer.parseInt(row.get(1));
@@ -150,8 +153,7 @@ public class PatternUtils {
 					}
 				}
 			}
-
-			System.out.println(patternOccFile.getAbsolutePath() + "\n" + patternFile.getAbsolutePath());
+			patterOcc.setRows(occRows);
 
 			CSVUtils.saveTable(patternTable, patternFile);
 			CSVUtils.saveTable(patterOcc, patternOccFile);