Package it.unimi.dsi.sux4j.bits
Interface Rank
 All Superinterfaces:
Serializable
 All Known Implementing Classes:
AbstractRank
,Rank11
,Rank11Original
,Rank12
,Rank16
,Rank9
,Rank9GogPetri
,RankSelect
,SparseRank
public interface Rank extends Serializable
A data structure providing ranking over a bit array.
Ranking is a basic building blocks for most succinct data structures. Usually, instances of this class class provide quick (e.g., constanttime) ranking.
This interface specifies a zerobased ranking. More precisely, rank is applied to a bit vector in
which bits positions are numbered starting from zero. Then, rank(p)
is the
number of of ones that precede position p
(the bit at position p
is not included
in the count).
The following properties always hold:
rank(0)=0
;rank(length())
is the number of ones in the bit vector.
 See Also:
Select

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
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.long
rankZero(long pos)
Returns the number of zeroes preceding the specified position.long
rankZero(long from, long to)
Returns the number of zeroes in the specified interval.

Method Details

count
long count()Returns the number of ones in the bit vector indexed by this class. Returns:
 number of ones in the bit vector indexed by this class.

rank
long rank(long pos)Returns the number of ones preceding the specified position. 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
; ifpos
is out of bounds, behavior is undefined.

rank
long rank(long from, long to)Returns the number of ones in the specified interval. 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 tofrom
. Returns:
 the number of ones between
from
(inclusive) andto
(exclusive); if the parameters are out of bounds, behavior is undefined.

rankZero
long rankZero(long pos)Returns the number of zeroes preceding the specified position. Parameters:
pos
 a position in the bit vector between 0 (inclusive) and the length of the bit vector (inclusive). Returns:
 the number of zeroes preceding
pos
; ifpos
is out of bounds, behavior is undefined.

rankZero
long rankZero(long from, long to)Returns the number of zeroes in the specified interval. 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 tofrom
. Returns:
 the number of zeros between
from
(inclusive) andto
(exclusive); if the parameters are out of bounds, behavior is undefined (might throw an exception).

bitVector
BitVector bitVector()Returns the bit vector indexed by this structure.Note that you must not modify the returned vector.
 Returns:
 the bit vector indexed by this structure.

numBits
long numBits()Returns the overall number of bits allocated by this structure. Returns:
 the overall number of bits allocated by this structure (not including the bits of the indexed vector).
