Module org.chocosolver

Package org.chocosolver.memory.structure

Class OneWordS32BitSet

java.lang.Object

org.chocosolver.memory.structure.OneWordS32BitSet

All Implemented Interfaces:

IStateBitSet

public class OneWordS32BitSet
extends Object
implements IStateBitSet

Constructor Summary

Constructors

Constructor	Description
OneWordS32BitSet(IEnvironment environment, int nbits)	Creates a bit set whose initial size is large enough to explicitly represent bits with indices in the range 0 through nbits-1.

Method Summary

Modifier and Type	Method	Description
int	cardinality()	Returns the number of bits set to true in this BitSet.
void	clear()	Sets all of the bits in this BitSet to false.
void	clear(int bitIndex)	Sets the bit specified by the index to false.
void	clear(int fromIndex, int toIndex)	Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to false.
boolean	equals(Object obj)
boolean	get(int bitIndex)	Returns the value of the bit with the specified index.
int	hashCode()
boolean	isEmpty()	Returns true if this BitSet contains no bits that are set to true.
int	length()	Returns the "logical size" of this BitSet: the index of the highest set bit in the BitSet plus one.
int	nextClearBit(int fromIndex)	Returns the index of the first bit that is set to false that occurs on or after the specified starting index.
int	nextSetBit(int fromIndex)	Returns the index of the first bit that is set to true that occurs on or after the specified starting index.
int	prevClearBit(int fromIndex)	Returns the index of the nearest bit that is set to false that occurs on or before the specified starting index.
int	prevSetBit(int fromIndex)	Returns the index of the nearest bit that is set to true that occurs on or before the specified starting index.
void	set(int bitIndex)	Sets the bit at the specified index to true.
void	set(int bitIndex, boolean value)	Sets the bit at the specified index to the specified value.
void	set(int fromIndex, int toIndex)	Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to true.
int	size()	Returns the number of bits of space actually in use by this BitSet to represent bit values.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

OneWordS32BitSet

public OneWordS32BitSet(IEnvironment environment,
                        int nbits)

Creates a bit set whose initial size is large enough to explicitly represent bits with indices in the range 0 through nbits-1. All bits are initially false.

Parameters:

environment - backtrackable environment

nbits - the initial size of the bit set.

Throws:

NegativeArraySizeException - if the specified initial size is negative.

Method Detail

set

public void set(int bitIndex)

Sets the bit at the specified index to true.

Specified by:

set in interface IStateBitSet

Parameters:

bitIndex - a bit index.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

Since:

JDK1.0

set

public void set(int bitIndex,
                boolean value)

Sets the bit at the specified index to the specified value.

Specified by:

set in interface IStateBitSet

Parameters:

bitIndex - a bit index.

value - a boolean value to set.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

Since:

1.4

set

public void set(int fromIndex,
                int toIndex)

Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to true.

Specified by:

set in interface IStateBitSet

Parameters:

fromIndex - index of the first bit to be set.

toIndex - index after the last bit to be set.

Throws:

IndexOutOfBoundsException - if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex.

Since:

1.4

clear

public void clear(int bitIndex)

Sets the bit specified by the index to false.

Specified by:

clear in interface IStateBitSet

Parameters:

bitIndex - the index of the bit to be cleared.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

Since:

JDK1.0

clear

public void clear(int fromIndex,
                  int toIndex)

Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to false.

Specified by:

clear in interface IStateBitSet

Parameters:

fromIndex - index of the first bit to be cleared.

toIndex - index after the last bit to be cleared.

Throws:

IndexOutOfBoundsException - if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex.

Since:

1.4

clear

public void clear()

Sets all of the bits in this BitSet to false.

Specified by:

clear in interface IStateBitSet

Since:

1.4

get

public final boolean get(int bitIndex)

Returns the value of the bit with the specified index. The value is true if the bit with the index bitIndex is currently set in this BitSet; otherwise, the result is false.

Specified by:

get in interface IStateBitSet

Parameters:

bitIndex - the bit index.

Returns:

the value of the bit with the specified index.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

nextSetBit

public int nextSetBit(int fromIndex)

Returns the index of the first bit that is set to true that occurs on or after the specified starting index. If no such bit exists then -1 is returned.

To iterate over the true bits in a BitSet, use the following loop:

 
 for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) {
     // operate on index i here
 }

Specified by:

nextSetBit in interface IStateBitSet

Parameters:

fromIndex - the index to start checking from (inclusive)

Returns:

the index of the next set bit, or -1 if there is no such bit

Throws:

IndexOutOfBoundsException - if the specified index is negative

Since:

1.4

nextClearBit

public int nextClearBit(int fromIndex)

Returns the index of the first bit that is set to false that occurs on or after the specified starting index.

Specified by:

nextClearBit in interface IStateBitSet

Parameters:

fromIndex - the index to start checking from (inclusive)

Returns:

the index of the next clear bit

Throws:

IndexOutOfBoundsException - if the specified index is negative

Since:

1.4

prevSetBit

public int prevSetBit(int fromIndex)

Returns the index of the nearest bit that is set to true that occurs on or before the specified starting index. If no such bit exists, or if -1 is given as the starting index, then -1 is returned.

To iterate over the true bits in a BitSet, use the following loop:

 
 for (int i = bs.length(); (i = bs.previousSetBit(i-1)) >= 0; ) {
     // operate on index i here
 }

Specified by:

prevSetBit in interface IStateBitSet

Parameters:

fromIndex - the index to start checking from (inclusive)

Returns:

the index of the previous set bit, or -1 if there is no such bit

Throws:

IndexOutOfBoundsException - if the specified index is less than -1

Since:

1.7

prevClearBit

public int prevClearBit(int fromIndex)

Returns the index of the nearest bit that is set to false that occurs on or before the specified starting index. If no such bit exists, or if -1 is given as the starting index, then -1 is returned.

Specified by:

prevClearBit in interface IStateBitSet

Parameters:

fromIndex - the index to start checking from (inclusive)

Returns:

the index of the previous clear bit, or -1 if there is no such bit

Throws:

IndexOutOfBoundsException - if the specified index is less than -1

Since:

1.7

length

public int length()

Returns the "logical size" of this BitSet: the index of the highest set bit in the BitSet plus one. Returns zero if the BitSet contains no set bits.

Returns:

the logical size of this BitSet.

Since:

1.2

isEmpty

public boolean isEmpty()

Returns true if this BitSet contains no bits that are set to true.

Specified by:

isEmpty in interface IStateBitSet

Returns:

boolean indicating whether this BitSet is empty.

Since:

1.4

cardinality

public int cardinality()

Returns the number of bits set to true in this BitSet.

Specified by:

cardinality in interface IStateBitSet

Returns:

the number of bits set to true in this BitSet.

Since:

1.4

hashCode

public int hashCode()

Overrides:

hashCode in class Object

size

public int size()

Returns the number of bits of space actually in use by this BitSet to represent bit values. The maximum element in the set is the size - 1st element.

Specified by:

size in interface IStateBitSet

Returns:

the number of bits currently in this bit set.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object