import java.util.HashSet;

import java.util.HashSet;

import org.apache.poi.hssf.record.ExtendedFormatRecord;

import org.apache.poi.hssf.record.ExtendedFormatRecord;

import org.apache.poi.hssf.record.FontRecord;

import org.apache.poi.hssf.record.FontRecord;

import org.apache.poi.hssf.record.common.UnicodeString;

import org.apache.poi.hssf.record.common.UnicodeString;

import org.apache.poi.ss.usermodel.Cell;

import org.apache.poi.ss.usermodel.Cell;

import org.apache.poi.ss.usermodel.Row;

import org.apache.poi.ss.usermodel.Row;

   public static void optimiseCellStyles(HSSFWorkbook workbook) {

   public static void optimiseCellStyles(HSSFWorkbook workbook) {

       // Where each style has ended up, and if we need to

       // Where each style has ended up, and if we need to

       //  delete the record for it. Start off with no change

       //  delete the record for it. Start off with no change

       boolean[] isUsed = new boolean[newPos.length];

       boolean[] isUsed = new boolean[newPos.length];

       boolean[] zapRecords = new boolean[newPos.length];

       boolean[] zapRecords = new boolean[newPos.length];

       for(int i=0; i<newPos.length; i++) {

       for(int i=0; i<newPos.length; i++) {

           isUsed[i] = false;

           isUsed[i] = false;

           newPos[i] = (short)i;

           newPos[i] = (short)i;

           zapRecords[i] = false;

           zapRecords[i] = false;

       }

       }

       // Get each style record, so we can do deletes

       // Get each style record, so we can do deletes

       //  without getting confused

       //  without getting confused

       ExtendedFormatRecord[] xfrs = new ExtendedFormatRecord[newPos.length]; 

       ExtendedFormatRecord[] xfrs = new ExtendedFormatRecord[newPos.length]; 

       for(int i=0; i<newPos.length; i++) {

       for(int i=0; i<newPos.length; i++) {

       }

       }

       // Loop over each style, seeing if it is the same

       // Loop over each style, seeing if it is the same

       //  later duplicate copy to the earlier one, and 

       //  later duplicate copy to the earlier one, and 

       //  mark the later one as needing deleting

       //  mark the later one as needing deleting

       // Only work on user added ones, which come after 20

       // Only work on user added ones, which come after 20

           // Check this one for being a duplicate

           // Check this one for being a duplicate

           //  of an earlier one

           //  of an earlier one

           int earlierDuplicate = -1;

           int earlierDuplicate = -1;

                   earlierDuplicate = j;

                   earlierDuplicate = j;

               }

               }

           }

           }

               newPos[i] = (short)earlierDuplicate;

               newPos[i] = (short)earlierDuplicate;

               zapRecords[i] = true;

               zapRecords[i] = true;

           }

           }

       }

       }

       // Loop over all the cells in the file, and identify any user defined

       // Loop over all the cells in the file, and identify any user defined

               for (Cell cellI : row) {

               for (Cell cellI : row) {

                   HSSFCell cell = (HSSFCell)cellI;

                   HSSFCell cell = (HSSFCell)cellI;

                   short oldXf = cell.getCellValueRecord().getXFIndex();

                   short oldXf = cell.getCellValueRecord().getXFIndex();

               }

               }

           }

           }

       }

       }

       // Mark any that aren't used as needing zapping

       // Mark any that aren't used as needing zapping

           if (! isUsed[i]) {

           if (! isUsed[i]) {

               // Un-used style, can be removed

               // Un-used style, can be removed

               zapRecords[i] = true;

               zapRecords[i] = true;

       //  deletes that have occurred between

       //  deletes that have occurred between

       //  the start and them

       //  the start and them

       // Only work on user added ones, which come after 20

       // Only work on user added ones, which come after 20

           // Find the number deleted to that

           // Find the number deleted to that

           //  point, and adjust

           //  point, and adjust

           short preDeletePos = newPos[i];

           short preDeletePos = newPos[i];

       // styles we did not intend to (the ones that _were_ duplicated and not the duplicates)

       // styles we did not intend to (the ones that _were_ duplicated and not the duplicates)

       int max = newPos.length;

       int max = newPos.length;

       int removed = 0; // to adjust index after deletion

       int removed = 0; // to adjust index after deletion

           if(zapRecords[i + removed]) {

           if(zapRecords[i + removed]) {

               i--;

               i--;

               max--;

               max--;

               removed++;

               removed++;

           }

           }

       }

       }

       // Finally, update the cells to point at their new extended format records

       // Finally, update the cells to point at their new extended format records

       for(int sheetNum=0; sheetNum<workbook.getNumberOfSheets(); sheetNum++) {

       for(int sheetNum=0; sheetNum<workbook.getNumberOfSheets(); sheetNum++) {

           HSSFSheet s = workbook.getSheetAt(sheetNum);

           HSSFSheet s = workbook.getSheetAt(sheetNum);