How to use

HuTuckerCodec

in

it.unimi.dsi.compression

@Deprecated
public PrefixCoder getCoder() { return coder(); }
@Deprecated

  @Deprecated
  public Decoder getDecoder() { return decoder(); }
}

public HuTuckerCodec( final int[] frequency ) {
  this( intArray2LongArray( frequency ) );
}

return new Object[] { new HuTuckerCodec( packedFrequency ).coder().codeWords(), char2symbol };

markRec(node[minLeft], 0);
root = rebuildTree(node[minLeft]);
decoder = new TreeDecoder(root, size);
coder = new CodeWordCoder(decoder.buildCodes());

codec = new HuTuckerCodec( packedFrequency );
prefixCoder = codec.coder();
decoder = codec.decoder();

/** Mark recursively the height of each node. */
private void markRec( final LevelNode n, final int height ) {
  if ( n == null ) return;
  n.level = height;
  markRec( (LevelNode) n.left, height + 1 );
  markRec( (LevelNode) n.right, height + 1 );
}

/** We scan recursively the tree, making a copy that uses lightweight nodes. */

private TreeDecoder.Node rebuildTree( final LevelNode n ) {
  if ( n == null ) return null;
  if ( n.symbol != -1 ) return new TreeDecoder.LeafNode( n.symbol );
  
  TreeDecoder.Node newNode = new TreeDecoder.Node();
  newNode.left = rebuildTree( (LevelNode) n.left );
  newNode.right = rebuildTree( (LevelNode) n.right );
  
  return newNode;
}

private static Object[] getCoder(final Iterable<? extends CharSequence> iterable, boolean prefixFree) {
  // First of all, we gather frequencies for all Unicode characters
  long[] frequency = new long[Character.MAX_VALUE + 1];
  int maxWordLength = 0;
  CharSequence s;
  int n = 0;
  for(Iterator<? extends CharSequence> i = iterable.iterator(); i.hasNext();) {
    s = i.next();
    maxWordLength = Math.max(s.length(), maxWordLength);
    for(int j = s.length(); j-- != 0;) frequency[s.charAt(j)]++;
    n++;
  }
  // Then, we compute the number of actually used characters. We count from the start the stop character.
  int count = prefixFree ? 1 : 0;
  for(int i = frequency.length; i-- != 0;) if (frequency[i] != 0) count++;
  /* Now we remap used characters in f, building at the same time the map from characters to symbols (except for the stop character). */
  long[] packedFrequency = new long[count];
  final Char2IntMap char2symbol = new Char2IntOpenHashMap(count);
  for(int i = frequency.length, k = count; i-- != 0;) {
    if (frequency[i] != 0) {
      packedFrequency[--k] = frequency[i];
      char2symbol.put((char)i, k);
    }
  }
  if (prefixFree) packedFrequency[0] = n; // The stop character appears once in each string.
  // We now build the coder used to code the strings
  return new Object[] { new HuTuckerCodec(packedFrequency).coder().codeWords(), char2symbol };
}

markRec( node[ minLeft ], 0 );
root = rebuildTree( node[ minLeft ] );
decoder = new TreeDecoder( root, size );
coder = new CodeWordCoder( decoder.buildCodes() );

codec = new HuTuckerCodec(packedFrequency);
prefixCoder = codec.coder();
decoder = codec.decoder();

/** Mark recursively the height of each node. */
private void markRec( final LevelNode n, final int height ) {
  if ( n == null ) return;
  n.level = height;
  markRec( (LevelNode) n.left, height + 1 );
  markRec( (LevelNode) n.right, height + 1 );
}

/** We scan recursively the tree, making a copy that uses lightweight nodes. */

private TreeDecoder.Node rebuildTree( final LevelNode n ) {
  if ( n == null ) return null;
  if ( n.symbol != -1 ) return new TreeDecoder.LeafNode( n.symbol );
  
  TreeDecoder.Node newNode = new TreeDecoder.Node();
  newNode.left = rebuildTree( (LevelNode) n.left );
  newNode.right = rebuildTree( (LevelNode) n.right );
  
  return newNode;
}

return new Object[] { new HuTuckerCodec( packedFrequency ).coder().codeWords(), char2symbol };

markRec( node[ minLeft ], 0 );
root = rebuildTree( node[ minLeft ] );
decoder = new TreeDecoder( root, size );
coder = new CodeWordCoder( decoder.buildCodes() );

codec = new HuTuckerCodec( packedFrequency );
prefixCoder = codec.coder();
decoder = codec.decoder();

/** Mark recursively the height of each node. */
private void markRec(final LevelNode n, final int height) {
  if (n == null) return;
  n.level = height;
  markRec((LevelNode) n.left, height + 1);
  markRec((LevelNode) n.right, height + 1);
}

/** We scan recursively the tree, making a copy that uses lightweight nodes. */
private TreeDecoder.Node rebuildTree(final LevelNode n) {
  if (n == null) return null;
  if (n.symbol != -1) return new TreeDecoder.LeafNode(n.symbol);
  TreeDecoder.Node newNode = new TreeDecoder.Node();
  newNode.left = rebuildTree((LevelNode) n.left);
  newNode.right = rebuildTree((LevelNode) n.right);
  return newNode;
}

@Deprecated
public PrefixCoder getCoder() { return coder(); }
@Deprecated

public HuTuckerCodec( final int[] frequency ) {
  this( intArray2LongArray( frequency ) );
}