Package it.unimi.dsi.sux4j.bits

Class Rank11

java.lang.Object
it.unimi.dsi.sux4j.bits.AbstractRank
it.unimi.dsi.sux4j.bits.Rank11
All Implemented Interfaces:
Rank, Serializable
public class Rank11 extends AbstractRank implements Rank
A rank11 implementation.

rank11 is a ranking structure using 6.25% additional space and providing very fast ranking. It was proposed by Simon Gog and Matthias Petri in “Optimized succinct data structures for massive data”, Softw. Pract. Exper., 2014. The only difference between this implementation and their rank_support_v5 is that counts for blocks are stored as in Rank9 (that is, in opposite order).

Note that to achieve such a low overhead, rank(long) contains a loop. As a consequence, the implementation of this method is significantly slower than that of Rank9 or Rank16, which don't do any looping.

See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected long[]
    bits
     
    protected final BitVector
    bitVector
     
    protected final long[]
    count
     
    protected final long
    lastOne
     
    protected final long
    numOnes
     
    protected final int
    numWords
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    Rank11(long[] bits, long length)
     
    Rank11(BitVector bitVector)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    BitVector
    bitVector()
    Returns the bit vector indexed by this structure.
    long
    count()
    Returns the number of ones in the bit vector indexed by this class.
    long
    lastOne()
     
    long
    numBits()
    Returns the overall number of bits allocated by this structure.
    long
    rank(long pos)
    Returns the number of ones preceding the specified position.
    long
    rank(long from, long to)
    Returns the number of ones in the specified interval.

    Methods inherited from class it.unimi.dsi.sux4j.bits.AbstractRank

    rankZero, rankZero

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface it.unimi.dsi.sux4j.bits.Rank

    rankZero, rankZero

  • Field Details

    • bits

      protected transient long[] bits

    • bitVector

      protected final BitVector bitVector

    • count

      protected final long[] count

    • numWords

      protected final int numWords

    • numOnes

      protected final long numOnes

    • lastOne

      protected final long lastOne

  • Constructor Details

    • Rank11

      public Rank11(long[] bits, long length)

    • Rank11

      public Rank11(BitVector bitVector)

  • Method Details

    • rank

      public long rank(long pos)
      Description copied from interface: Rank
      Returns the number of ones preceding the specified position.
      Specified by:
      rank in interface Rank
      Parameters:
      pos - a position in the bit vector between 0 (inclusive) and the length of the bit vector (inclusive).
      Returns:
      the number of ones preceding position pos; if pos is out of bounds, behavior is undefined.

    • numBits

      public long numBits()
      Description copied from interface: Rank
      Returns the overall number of bits allocated by this structure.
      Specified by:
      numBits in interface Rank
      Returns:
      the overall number of bits allocated by this structure (not including the bits of the indexed vector).

    • count

      public long count()
      Description copied from interface: Rank
      Returns the number of ones in the bit vector indexed by this class.
      Specified by:
      count in interface Rank
      Overrides:
      count in class AbstractRank
      Returns:
      number of ones in the bit vector indexed by this class.

    • rank

      public long rank(long from, long to)
      Description copied from interface: Rank
      Returns the number of ones in the specified interval.
      Specified by:
      rank in interface Rank
      Overrides:
      rank in class AbstractRank
      Parameters:
      from - a position in the bit vector between 0 (inclusive) and the length of the bit vector (inclusive).
      to - a position in the bit vector between 0 (inclusive) and the length of the bit vector (inclusive); must be greater than or equal to from.
      Returns:
      the number of ones between from (inclusive) and to (exclusive); if the parameters are out of bounds, behavior is undefined.

    • lastOne

      public long lastOne()

    • bitVector

      public BitVector bitVector()
      Description copied from interface: Rank
      Returns the bit vector indexed by this structure.

      Note that you must not modify the returned vector.

      Specified by:
      bitVector in interface Rank
      Returns:
      the bit vector indexed by this structure.