ch.randelshofer.math
Class IntMath

java.lang.Object
  ch.randelshofer.math.IntMath

public class IntMath
extends java.lang.Object

Utility class for integer arithmetic.

Version:

1.1 2009-12-27 Added gcd(long,long).
1.0 2002-05-01

Author:

Werner Randelshofer

Constructor Summary

IntMath()
Creates a new instance of IntMath

Method Summary

static int	gcd(int a, int b) Returns an int whose value is the greatest common divisor of abs(a) and abs(b).
static long	gcd(long a, long b) Returns a long whose value is the greatest common divisor of abs(a) and abs(b).
static void	main(java.lang.String[] args)
static int	reverseBits(int a) Reverses all 32 bits of the provided integer value.
static int	reverseBits(int a, int numBits) Reverses specified number of bits of the provided integer value.
static int	scm(int a, int b) Returns an int whose value is the smallest common multiple of abs(a) and abs(b).

Methods inherited from class java.lang.Object

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

Constructor Detail

IntMath

public IntMath()

Creates a new instance of IntMath

Method Detail

gcd

public static int gcd(int a,
                      int b)

Returns an int whose value is the greatest common divisor of abs(a) and abs(b). Returns 0 if a==0 && b==0.

Parameters:

a - value with with the GCD is to be computed.

b - value with with the GCD is to be computed.

Returns:

GCD(a, b)

gcd

public static long gcd(long a,
                       long b)

Returns a long whose value is the greatest common divisor of abs(a) and abs(b). Returns 0 if a==0 && b==0.

Parameters:

a - value with with the GCD is to be computed.

b - value with with the GCD is to be computed.

Returns:

GCD(a, b)

scm

public static int scm(int a,
                      int b)

Returns an int whose value is the smallest common multiple of abs(a) and abs(b). Returns 0 if a==0 || b==0.

Parameters:

a - value with with the SCM is to be computed.

b - value with with the SCM is to be computed.

Returns:

SCM(a, b)

reverseBits

public static int reverseBits(int a)

Reverses all 32 bits of the provided integer value.

reverseBits

public static int reverseBits(int a,
                              int numBits)

Reverses specified number of bits of the provided integer value.

Parameters:

a - The number.

numBits - The number of bits (must be between 1 and 32).

main

public static void main(java.lang.String[] args)