com.vcollaborate.bitwise

Class BinaryUtils

java.lang.Object

com.vcollaborate.bitwise.BinaryUtils

public final class BinaryUtils
extends Object

Method Summary

Modifier and Type	Method and Description
static long	allOnes(long length) Returns a value with all bits set to 1 of length length.
static long	fromBitSet(BitSet bits) Converts the BitSet bits into a long value.
static long[]	getAllPermutations(int bits, int length) Returns an array containing all permutations of a defined bitset with bits set and maximum length of length.
static int[]	getBitsSet(long val) Returns the number of bits set.
static int	getHammingDistance(long val1, long val2) Calculates the hamming distance between the two given values.
static boolean	isBitSet(long val, int pos) Determines if the bit at position pos in the value val is set.
static long	nextPermutation(long val) Compute the lexicographically next bit permutation.
static BitSet	toBitSet(int size, long value) Converts value into a BitSet of size size.

Methods inherited from class java.lang.Object

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

Method Detail

toBitSet

public static final BitSet toBitSet(int size,
                                    long value)

Converts value into a BitSet of size size.

fromBitSet

public static final long fromBitSet(BitSet bits)

Converts the BitSet bits into a long value.

This is the reverse operation from toBitSet(int, long).

nextPermutation

public static final long nextPermutation(long val)

Compute the lexicographically next bit permutation. Suppose we have a pattern of N bits set to 1 in an integer and we want the next permutation of N 1 bits in a lexicographical sense. For example, if N is 3 and the bit pattern is 00010011, the next patterns would be 00010101, 00010110, 00011001,00011010, 00011100, 00100011, and so forth.

getAllPermutations

public static final long[] getAllPermutations(int bits,
                                              int length)

Returns an array containing all permutations of a defined bitset with bits set and maximum length of length.

getHammingDistance

public static final int getHammingDistance(long val1,
                                           long val2)

Calculates the hamming distance between the two given values.

allOnes

public static final long allOnes(long length)

Returns a value with all bits set to 1 of length length.

isBitSet

public static final boolean isBitSet(long val,
                                     int pos)

Determines if the bit at position pos in the value val is set.

getBitsSet

public static final int[] getBitsSet(long val)

Returns the number of bits set.