DataStructures
Class Random

java.lang.Object
  |
  +--DataStructures.Random

public class Random

extends java.lang.Object

Random number class, using a 31-bit linear congruential generator. Note that java.util contains a class Random, so watch out for name conflicts.

Constructor Summary

Random()
Construct this Random object with initial state obtained from system clock.

Random(int initialValue)
Construct this Random object with specified initial state.

Method Summary

static void	main(java.lang.String[] args)
static void	permute(java.lang.Object[] a) Randomly rearrange an array.
double	random0_1() Return a pseudorandom double in the open range 0..1 and change the internal state.
int	randomInt() Return a pseudorandom int, and change the internal state.
int	randomInt(int low, int high) Return an int in the closed range [low,high], and change the internal state.
int	randomIntWRONG() Return a pseudorandom int, and change the internal state.
long	randomLong(long low, long high) Return an long in the closed range [low,high], and change the internal state.

Methods inherited from class java.lang.Object

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

Constructor Detail

Random

public Random()

Construct this Random object with initial state obtained from system clock.

Random

public Random(int initialValue)

Construct this Random object with specified initial state.

Parameters:

initialValue - the initial state.

Method Detail

randomInt

public int randomInt()

Return a pseudorandom int, and change the internal state.

Returns:

the pseudorandom int.

randomIntWRONG

public int randomIntWRONG()

Return a pseudorandom int, and change the internal state. DOES NOT WORK.

Returns:

the pseudorandom int.

random0_1

public double random0_1()

Return a pseudorandom double in the open range 0..1 and change the internal state.

Returns:

the pseudorandom double.

randomInt

public int randomInt(int low,
                     int high)

Return an int in the closed range [low,high], and change the internal state.

Parameters:

low - the minimum value returned.

high - the maximum value returned.

Returns:

the pseudorandom int.

randomLong

public long randomLong(long low,
                       long high)

Return an long in the closed range [low,high], and change the internal state.

Parameters:

low - the minimum value returned.

high - the maximum value returned.

Returns:

the pseudorandom long.

permute

public static final void permute(java.lang.Object[] a)

Randomly rearrange an array. The random numbers used depend on the time and day.

Parameters:

a - the array.

main

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