[u/mrichter/AliRoot.git] / TPC / AliTPCHuffman.cxx

/**************************************************************************
 * Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/
/* $Id:*/
////////////////////////////////////////////////
//  Huffman classes for set:TPC               //
////////////////////////////////////////////////
//This file contains two classes and it implements 
//the Huffman algorithm for creating tables
//used in the compression phase.
//The class AliTPCHNode represents a node of the Huffman tree, while
//the class AliTPCHTable represents a compression table


#include <TObjArray.h>
#include "Riostream.h"
#include "TMath.h"
#include "AliTPCHuffman.h"
#include "AliTPCBuffer160.h"

ClassImp(AliTPCHNode)

AliTPCHNode::AliTPCHNode(){
  //Constructor
  fLeft=0;
  fRight=0;
}

//////////////////////////////////////////////////////////////////////////////

AliTPCHNode::AliTPCHNode(Int_t sym, Double_t freq){
  //Standard constructor
  fSymbol=sym;
  fFrequency=freq;
  fLeft=0;
  fRight=0;
}

//////////////////////////////////////////////////////////////////////////////

AliTPCHNode::AliTPCHNode(const AliTPCHNode &source){
  //Copy Constructor 
  if(&source == this) return;
  this->fSymbol = source.fSymbol;
  this->fFrequency = source.fFrequency;
  this->fLeft = source.fLeft;
  this->fRight = source.fRight;
  return;
}

//////////////////////////////////////////////////////////////////////////////

AliTPCHNode& AliTPCHNode::operator=(const AliTPCHNode &source){
  //Assignment operator
  if(&source == this) return *this;
  this->fSymbol = source.fSymbol;
  this->fFrequency = source.fFrequency;
  this->fLeft = source.fLeft;
  this->fRight = source.fRight;
  return *this;
}

//////////////////////////////////////////////////////////////////////////////

Int_t AliTPCHNode::Compare(const TObject *obj)const{
  //Function called by Sort method of TObjArray
  AliTPCHNode *node=(AliTPCHNode *)obj;
  Double_t f=fFrequency;
  Double_t fo=node->fFrequency;
  if (f<fo) return 1;
  else if (f>fo) return -1;
  else return 0;
}

//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////

ClassImp(AliTPCHTable)
  
AliTPCHTable::AliTPCHTable(){
  //Constructor
  fCodeLen=0;
  fCode=0;
  fHNodes=0;
  fNnodes=0;
  fNum=0;
  fVerbose=0;
}

//////////////////////////////////////////////////////////////////////////////

AliTPCHTable::AliTPCHTable(Int_t size){
  //Initialization
  fSize=size;
  fCodeLen = new UChar_t[fSize]; 
  fCode = new Double_t[fSize]; 
  fHNodes = new TObjArray;
  fNnodes=0;
  fNum=0;
  fVerbose=0;
  fSym= new Short_t[fSize];
  for (Short_t i=0;i<fSize;i++) {
    fSym[i]=i;
  }//end for
  ClearTable(); 
}

//////////////////////////////////////////////////////////////////////////////

AliTPCHTable::AliTPCHTable(const AliTPCHTable &source){
  //Copy Constructor 
  if(&source == this) return;
  this->fSize = source.fSize;
  this->fCodeLen = source.fCodeLen;
  this->fCode = source.fCode;
  this->fSym = source.fSym;
  this->fHNodes = source.fHNodes;
  this->fNnodes = source.fNnodes;
  this->fNum=source.fNum;
  this->fVerbose=source.fVerbose;
  return;
}

//////////////////////////////////////////////////////////////////////////////

AliTPCHTable& AliTPCHTable::operator=(const AliTPCHTable &source) {
  //Assignment operator
  if(&source == this) return *this;
  this->fSize = source.fSize;
  this->fCodeLen = source.fCodeLen;
  this->fCode = source.fCode;
  this->fSym = source.fSym;
  this->fHNodes = source.fHNodes;
  this->fNnodes = source.fNnodes;
  this->fNum=source.fNum;
  this->fVerbose=source.fVerbose;
  return *this;
}

//////////////////////////////////////////////////////////////////////////////

AliTPCHTable::~AliTPCHTable(){
  //HTable destructor
  if(fVerbose)
    cout<<"HTable destructor !\n";
  if (fCodeLen) delete[] fCodeLen;
  if (fCode) delete [] fCode;
  if (fHNodes) {
    fHNodes->Delete(); //Clear out the collection and deletes the removed objects
    delete fHNodes;
  }//end if
}

//////////////////////////////////////////////////////////////////////////////

void AliTPCHTable::SetCodeLen(UChar_t len,Int_t val){
  //Sets codelength of "val" to the variable "len"
  fCodeLen[val]=len;
  return;
}

//////////////////////////////////////////////////////////////////////////////

void AliTPCHTable::SetCode(Double_t code,Int_t val){
  //Sets the binary code of the variable "val"
  fCode[val]=code;
  return;
}

//////////////////////////////////////////////////////////////////////////////

void AliTPCHTable::PrintTable()const{
  //This method prints a table
  cout<<"Table for Huffman coding\n";
  cout<<"  Symbol|   Code   |   Length \n";
  for (Int_t i=0;i<fSize;i++){
    if (fCodeLen[i]){
      cout.width(6);cout<<fSym[i];
      cout.width(3);cout<<"|";
      cout.width(6);cout<<hex<<(ULong_t)fCode[i]<<dec;
      cout.width(5);cout<<"|";
      cout.width(6);cout<<(ULong_t)fCodeLen[i]<<endl;  
    }//end if
  }//end for
}

//////////////////////////////////////////////////////////////////////////////

Bool_t AliTPCHTable::SpanTree(AliTPCHNode *start, ULong_t code, UChar_t len){
  //Hoffman codes are generated spanning the Huffman tree
  //In an Huffman tree any internal node has always two children
  AliTPCHNode * visited;
  visited = start;
  Int_t idx=visited->GetSymbol();
  if (!visited->GetLeft()) {
    fCode[idx] = code; 
    fCodeLen[idx] = len;
    return kTRUE;
  }//end if
  SpanTree(visited->GetLeft(), code << 1, len + 1);
  SpanTree(visited->GetRight(), code << 1 | 0x0001, len + 1);
  return kTRUE;
}

//////////////////////////////////////////////////////////////////////////////

void AliTPCHTable::ResetHNodes(){
  //Reset number of HNodes and the HNodes array 
  if (fHNodes)  fHNodes->Clear();
  if (fNnodes)  fNnodes=0;
}

//////////////////////////////////////////////////////////////////////////////

void AliTPCHTable::ClearTable(){
  //Clear the table
  memset(fCodeLen,0,sizeof(UChar_t)*fSize);
  memset(fCode,0,sizeof(Double_t)*fSize);
}

//////////////////////////////////////////////////////////////////////////////

Int_t  AliTPCHTable::GetFrequencies(const char *fname){
  //It fills the "fCode" array with the frequencies of the symbols read from the file
  AliTPCBuffer160 buff(fname,0);
  ULong_t numberOfWords=0;
  Int_t val;
  while((val=buff.GetNext())!=-1){
    fCode[val]++;
    fNum++;
    numberOfWords++;
  }
  cout<<"Total number of words: "<<numberOfWords<<endl;
  //Print out the frequencies 
  /*
    for (Int_t i=0;i<fSize;i++){
    if (fCode[i])cout<<"Symbol: "<<i<<" Freq: "<<fCode[i]<<endl;
    }
    cout<<endl;
  */
  return 0;
}

Int_t AliTPCHTable::SetValFrequency(const Int_t Val,Double_t Value){
  //This method sets to "Value" the frequency of the symbol "Val"
  fCode[Val]=Value;
  fNum=1;
  return 0;
}

//////////////////////////////////////////////////////////////////////////////

Int_t AliTPCHTable::SetFrequency(const Int_t Val){
  //It increments by one the frequency of the symbol "Val" whose frequency is 
  //stored in the fCode array
  fCode[Val]++;
  fNum++;
  return 0;
}

//////////////////////////////////////////////////////////////////////////////

Int_t AliTPCHTable::StoreFrequencies(const char *fname)const{
  //It stores the frequencies in a text file
  ofstream ftxt(fname);  
  for (Int_t i=0;i<fSize;i++){
    ftxt<<(ULong_t)fCode[i]<<endl;
  }
  ftxt.close();
  return 0;
}

//////////////////////////////////////////////////////////////////////////////

void AliTPCHTable::CompleteTable(Int_t k){
  //According to the kind of table (0..4) it associates a dummy frequency (1) to 
  //every symbols whose real frequency is zero, in a given range 0..max
  Int_t max;
  ULong_t val;
  switch(k){
  case 0:
    max=700;
    val=1;
    break;
  case 1:
    max=445;
    val=1;
    break;
  default:
    max=fSize;
    val=1;
    break;
  }//end switch

  for(Int_t i=0;i<max;i++){
    if(fCode[i]==0.0)fCode[i]=val;
  }
  return;
}

//////////////////////////////////////////////////////////////////////////////

Double_t  AliTPCHTable::GetEntropy()const{
  //This method calculates the value of the entropy 
  Double_t entropy=0;
  Double_t prob=0;
  for (Int_t i=0;i<fSize;i++){
    if (fCode[i]){
      prob=fCode[i]/(Double_t)fNum;
      entropy+=prob*(TMath::Log2(prob));
    }
  }
  return -entropy;
}

//////////////////////////////////////////////////////////////////////////////

Int_t AliTPCHTable::BuildHTable(){
  //It builds a Huffman tree 
  if(GetWordsNumber()){
    for (Int_t i=0; i< fSize; i++) {
      if (fCode[i] > 0.){
	fNnodes++;
	//cout<< "Symbol:"<<i<<" Freq:"<<fCode[i]<<endl;
	fHNodes->Add(new AliTPCHNode(i,fCode[i]));
      }//end if
    }//end for
    Int_t nentries=fHNodes->GetEntriesFast();  
    //cout<<"Number of symbols: "<<nentries<<endl;
    Int_t nindex=nentries-1;  
    while (nindex > 0){
      fHNodes->Sort(nindex+1);
      AliTPCHNode *aux = new AliTPCHNode(0,0);
      AliTPCHNode *node= (AliTPCHNode*)fHNodes->UncheckedAt(nindex-1);
      AliTPCHNode *node1= (AliTPCHNode*)fHNodes->UncheckedAt(nindex);
      
      aux->SetLeft(node);
      aux->SetRight(node1);
      aux->SetFrequency(node->GetFrequency() + node1->GetFrequency());
      fHNodes->RemoveAt(nindex-1);
      fHNodes->AddAt(aux,nindex-1);
      nindex--;
    }//end while
    ClearTable();  
    AliTPCHNode *start= (AliTPCHNode*)fHNodes->UncheckedAt(0);
    SpanTree(start,0,0);
  }//end if
  else{
    cout<<"Table contains 0 elements\n";
  }//end else
  return 0;
}
//////////////////////////////////////////////////////////////////////////////
Commit	Line	Data
2e9f335b	1	/**************************************************************************
	2	* Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	8	* documentation strictly for non-commercial purposes is hereby granted *
	9	* without fee, provided that the above copyright notice appears in all *
	10	* copies and that both the copyright notice and this permission notice *
	11	* appear in the supporting documentation. The authors make no claims *
	12	* about the suitability of this software for any purpose. It is *
	13	* provided "as is" without express or implied warranty. *
	14	**************************************************************************/
a79660fb	15	/* $Id:*/
2e9f335b	16	////////////////////////////////////////////////
	17	// Huffman classes for set:TPC //
	18	////////////////////////////////////////////////
a79660fb	19	//This file contains two classes and it implements
	20	//the Huffman algorithm for creating tables
	21	//used in the compression phase.
	22	//The class AliTPCHNode represents a node of the Huffman tree, while
	23	//the class AliTPCHTable represents a compression table
	24
2e9f335b	25
2e9f335b	26	#include <TObjArray.h>
0f0615a3	27	#include "Riostream.h"
2e9f335b	28	#include "TMath.h"
	29	#include "AliTPCHuffman.h"
	30	#include "AliTPCBuffer160.h"
	31
	32	ClassImp(AliTPCHNode)
	33
	34	AliTPCHNode::AliTPCHNode(){
a79660fb	35	//Constructor
2e9f335b	36	fLeft=0;
	37	fRight=0;
	38	}
	39
	40	//////////////////////////////////////////////////////////////////////////////
	41
	42	AliTPCHNode::AliTPCHNode(Int_t sym, Double_t freq){
a79660fb	43	//Standard constructor
2e9f335b	44	fSymbol=sym;
	45	fFrequency=freq;
	46	fLeft=0;
	47	fRight=0;
	48	}
	49
	50	//////////////////////////////////////////////////////////////////////////////
	51
	52	AliTPCHNode::AliTPCHNode(const AliTPCHNode &source){
a79660fb	53	//Copy Constructor
2e9f335b	54	if(&source == this) return;
	55	this->fSymbol = source.fSymbol;
	56	this->fFrequency = source.fFrequency;
	57	this->fLeft = source.fLeft;
	58	this->fRight = source.fRight;
	59	return;
	60	}
	61
	62	//////////////////////////////////////////////////////////////////////////////
	63
	64	AliTPCHNode& AliTPCHNode::operator=(const AliTPCHNode &source){
a79660fb	65	//Assignment operator
2e9f335b	66	if(&source == this) return *this;
	67	this->fSymbol = source.fSymbol;
	68	this->fFrequency = source.fFrequency;
	69	this->fLeft = source.fLeft;
	70	this->fRight = source.fRight;
	71	return *this;
	72	}
	73
	74	//////////////////////////////////////////////////////////////////////////////
	75
	76	Int_t AliTPCHNode::Compare(const TObject *obj)const{
a79660fb	77	//Function called by Sort method of TObjArray
2e9f335b	78	AliTPCHNode node=(AliTPCHNode )obj;
	79	Double_t f=fFrequency;
	80	Double_t fo=node->fFrequency;
	81	if (f<fo) return 1;
	82	else if (f>fo) return -1;
	83	else return 0;
	84	}
	85
	86	//////////////////////////////////////////////////////////////////////////////
	87	//////////////////////////////////////////////////////////////////////////////
	88	//////////////////////////////////////////////////////////////////////////////
	89
	90	ClassImp(AliTPCHTable)
	91
	92	AliTPCHTable::AliTPCHTable(){
a79660fb	93	//Constructor
2e9f335b	94	fCodeLen=0;
	95	fCode=0;
	96	fHNodes=0;
	97	fNnodes=0;
	98	fNum=0;
	99	fVerbose=0;
	100	}
	101
	102	//////////////////////////////////////////////////////////////////////////////
	103
	104	AliTPCHTable::AliTPCHTable(Int_t size){
a79660fb	105	//Initialization
2e9f335b	106	fSize=size;
	107	fCodeLen = new UChar_t[fSize];
	108	fCode = new Double_t[fSize];
	109	fHNodes = new TObjArray;
	110	fNnodes=0;
	111	fNum=0;
	112	fVerbose=0;
	113	fSym= new Short_t[fSize];
	114	for (Short_t i=0;i<fSize;i++) {
	115	fSym[i]=i;
	116	}//end for
	117	ClearTable();
	118	}
	119
	120	//////////////////////////////////////////////////////////////////////////////
	121
	122	AliTPCHTable::AliTPCHTable(const AliTPCHTable &source){
a79660fb	123	//Copy Constructor
2e9f335b	124	if(&source == this) return;
	125	this->fSize = source.fSize;
	126	this->fCodeLen = source.fCodeLen;
	127	this->fCode = source.fCode;
	128	this->fSym = source.fSym;
	129	this->fHNodes = source.fHNodes;
	130	this->fNnodes = source.fNnodes;
	131	this->fNum=source.fNum;
	132	this->fVerbose=source.fVerbose;
	133	return;
	134	}
	135
	136	//////////////////////////////////////////////////////////////////////////////
	137
	138	AliTPCHTable& AliTPCHTable::operator=(const AliTPCHTable &source) {
a79660fb	139	//Assignment operator
2e9f335b	140	if(&source == this) return *this;
	141	this->fSize = source.fSize;
	142	this->fCodeLen = source.fCodeLen;
	143	this->fCode = source.fCode;
	144	this->fSym = source.fSym;
	145	this->fHNodes = source.fHNodes;
	146	this->fNnodes = source.fNnodes;
	147	this->fNum=source.fNum;
	148	this->fVerbose=source.fVerbose;
	149	return *this;
	150	}
	151
	152	//////////////////////////////////////////////////////////////////////////////
	153
	154	AliTPCHTable::~AliTPCHTable(){
a79660fb	155	//HTable destructor
2e9f335b	156	if(fVerbose)
	157	cout<<"HTable destructor !\n";
	158	if (fCodeLen) delete[] fCodeLen;
	159	if (fCode) delete [] fCode;
	160	if (fHNodes) {
	161	fHNodes->Delete(); //Clear out the collection and deletes the removed objects
	162	delete fHNodes;
	163	}//end if
	164	}
	165
	166	//////////////////////////////////////////////////////////////////////////////
	167
	168	void AliTPCHTable::SetCodeLen(UChar_t len,Int_t val){
a79660fb	169	//Sets codelength of "val" to the variable "len"
2e9f335b	170	fCodeLen[val]=len;
	171	return;
	172	}
	173
	174	//////////////////////////////////////////////////////////////////////////////
	175
	176	void AliTPCHTable::SetCode(Double_t code,Int_t val){
a79660fb	177	//Sets the binary code of the variable "val"
2e9f335b	178	fCode[val]=code;
	179	return;
	180	}
	181
	182	//////////////////////////////////////////////////////////////////////////////
	183
	184	void AliTPCHTable::PrintTable()const{
a79660fb	185	//This method prints a table
2e9f335b	186	cout<<"Table for Huffman coding\n";
	187	cout<<" Symbol\| Code \| Length \n";
	188	for (Int_t i=0;i<fSize;i++){
	189	if (fCodeLen[i]){
	190	cout.width(6);cout<<fSym[i];
	191	cout.width(3);cout<<"\|";
	192	cout.width(6);cout<<hex<<(ULong_t)fCode[i]<<dec;
	193	cout.width(5);cout<<"\|";
	194	cout.width(6);cout<<(ULong_t)fCodeLen[i]<<endl;
	195	}//end if
	196	}//end for
	197	}
	198
	199	//////////////////////////////////////////////////////////////////////////////
	200
	201	Bool_t AliTPCHTable::SpanTree(AliTPCHNode *start, ULong_t code, UChar_t len){
a79660fb	202	//Hoffman codes are generated spanning the Huffman tree
2e9f335b	203	//In an Huffman tree any internal node has always two children
	204	AliTPCHNode * visited;
	205	visited = start;
	206	Int_t idx=visited->GetSymbol();
	207	if (!visited->GetLeft()) {
	208	fCode[idx] = code;
	209	fCodeLen[idx] = len;
	210	return kTRUE;
	211	}//end if
	212	SpanTree(visited->GetLeft(), code << 1, len + 1);
	213	SpanTree(visited->GetRight(), code << 1 \| 0x0001, len + 1);
	214	return kTRUE;
	215	}
	216
	217	//////////////////////////////////////////////////////////////////////////////
	218
	219	void AliTPCHTable::ResetHNodes(){
a79660fb	220	//Reset number of HNodes and the HNodes array
2e9f335b	221	if (fHNodes) fHNodes->Clear();
	222	if (fNnodes) fNnodes=0;
	223	}
	224
	225	//////////////////////////////////////////////////////////////////////////////
	226
	227	void AliTPCHTable::ClearTable(){
a79660fb	228	//Clear the table
2e9f335b	229	memset(fCodeLen,0,sizeof(UChar_t)*fSize);
	230	memset(fCode,0,sizeof(Double_t)*fSize);
	231	}
	232
	233	//////////////////////////////////////////////////////////////////////////////
	234
	235	Int_t AliTPCHTable::GetFrequencies(const char *fname){
a79660fb	236	//It fills the "fCode" array with the frequencies of the symbols read from the file
2e9f335b	237	AliTPCBuffer160 buff(fname,0);
a79660fb	238	ULong_t numberOfWords=0;
	239	Int_t val;
	240	while((val=buff.GetNext())!=-1){
	241	fCode[val]++;
2e9f335b	242	fNum++;
a79660fb	243	numberOfWords++;
2e9f335b	244	}
a79660fb	245	cout<<"Total number of words: "<<numberOfWords<<endl;
2e9f335b	246	//Print out the frequencies
	247	/*
	248	for (Int_t i=0;i<fSize;i++){
	249	if (fCode[i])cout<<"Symbol: "<<i<<" Freq: "<<fCode[i]<<endl;
	250	}
	251	cout<<endl;
	252	*/
	253	return 0;
	254	}
	255
	256	Int_t AliTPCHTable::SetValFrequency(const Int_t Val,Double_t Value){
a79660fb	257	//This method sets to "Value" the frequency of the symbol "Val"
2e9f335b	258	fCode[Val]=Value;
	259	fNum=1;
	260	return 0;
	261	}
	262
	263	//////////////////////////////////////////////////////////////////////////////
	264
	265	Int_t AliTPCHTable::SetFrequency(const Int_t Val){
a79660fb	266	//It increments by one the frequency of the symbol "Val" whose frequency is
a79660fb	267	//stored in the fCode array
2e9f335b	268	fCode[Val]++;
	269	fNum++;
	270	return 0;
	271	}
	272
	273	//////////////////////////////////////////////////////////////////////////////
	274
a79660fb	275	Int_t AliTPCHTable::StoreFrequencies(const char *fname)const{
a79660fb	276	//It stores the frequencies in a text file
2e9f335b	277	ofstream ftxt(fname);
	278	for (Int_t i=0;i<fSize;i++){
	279	ftxt<<(ULong_t)fCode[i]<<endl;
	280	}
	281	ftxt.close();
	282	return 0;
	283	}
	284
	285	//////////////////////////////////////////////////////////////////////////////
	286
	287	void AliTPCHTable::CompleteTable(Int_t k){
a79660fb	288	//According to the kind of table (0..4) it associates a dummy frequency (1) to
a79660fb	289	//every symbols whose real frequency is zero, in a given range 0..max
2e9f335b	290	Int_t max;
	291	ULong_t val;
	292	switch(k){
	293	case 0:
	294	max=700;
	295	val=1;
	296	break;
	297	case 1:
	298	max=445;
	299	val=1;
	300	break;
	301	default:
	302	max=fSize;
	303	val=1;
	304	break;
	305	}//end switch
	306
	307	for(Int_t i=0;i<max;i++){
	308	if(fCode[i]==0.0)fCode[i]=val;
	309	}
	310	return;
	311	}
	312
	313	//////////////////////////////////////////////////////////////////////////////
	314
	315	Double_t AliTPCHTable::GetEntropy()const{
a79660fb	316	//This method calculates the value of the entropy
2e9f335b	317	Double_t entropy=0;
	318	Double_t prob=0;
	319	for (Int_t i=0;i<fSize;i++){
	320	if (fCode[i]){
	321	prob=fCode[i]/(Double_t)fNum;
	322	entropy+=prob*(TMath::Log2(prob));
	323	}
	324	}
	325	return -entropy;
	326	}
	327
	328	//////////////////////////////////////////////////////////////////////////////
	329
	330	Int_t AliTPCHTable::BuildHTable(){
a79660fb	331	//It builds a Huffman tree
2e9f335b	332	if(GetWordsNumber()){
	333	for (Int_t i=0; i< fSize; i++) {
	334	if (fCode[i] > 0.){
	335	fNnodes++;
	336	//cout<< "Symbol:"<<i<<" Freq:"<<fCode[i]<<endl;
	337	fHNodes->Add(new AliTPCHNode(i,fCode[i]));
	338	}//end if
	339	}//end for
	340	Int_t nentries=fHNodes->GetEntriesFast();
	341	//cout<<"Number of symbols: "<<nentries<<endl;
	342	Int_t nindex=nentries-1;
	343	while (nindex > 0){
	344	fHNodes->Sort(nindex+1);
	345	AliTPCHNode *aux = new AliTPCHNode(0,0);
	346	AliTPCHNode node= (AliTPCHNode)fHNodes->UncheckedAt(nindex-1);
	347	AliTPCHNode node1= (AliTPCHNode)fHNodes->UncheckedAt(nindex);
	348
	349	aux->SetLeft(node);
	350	aux->SetRight(node1);
	351	aux->SetFrequency(node->GetFrequency() + node1->GetFrequency());
	352	fHNodes->RemoveAt(nindex-1);
	353	fHNodes->AddAt(aux,nindex-1);
	354	nindex--;
	355	}//end while
	356	ClearTable();
	357	AliTPCHNode start= (AliTPCHNode)fHNodes->UncheckedAt(0);
	358	SpanTree(start,0,0);
	359	}//end if
	360	else{
	361	cout<<"Table contains 0 elements\n";
	362	}//end else
	363	return 0;
	364	}
2e9f335b	365	//////////////////////////////////////////////////////////////////////////////