shh.gl4
Class ZModNData

Object
  ZModNData

public class ZModNData

extends Object

A small database of facts about the ring Z/NZ.

Author:

Mark McConnell

Field Summary

int	cardP3 The number of points in P3(Z/NZ).
int	N

Constructor Summary

ZModNData(int N)
Constructor.

Method Summary

int	getInverse(int i) Returns the inverse of i modulo N, or 0 if i is not a unit mod N.
ArrayList	getUnits() Returns a list of the units mod N, as Integers.
static void	main(String[] args) Prints out all the data.

Methods inherited from class Object

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

Field Detail

N

public final int N

cardP3

public final int cardP3

The number of points in P³(Z/NZ). When N is prime, this is the usual projective three-space over the finite field. See PPT for what it is in general.

Constructor Detail

ZModNData

public ZModNData(int N)

Constructor.

Throws:

IllegalArgumentException - If N ≤ 1.

ArithmeticException - If N is so big that cardP3 would not fit in an int.

Method Detail

getUnits

public ArrayList getUnits()

Returns a list of the units mod N, as Integers. The values are between 1 and N-1 and sorted by <. A fresh list is returned every time.

getInverse

public int getInverse(int i)

Returns the inverse of i modulo N, or 0 if i is not a unit mod N. Expects 0 ≤ i < N.

main

public static void main(String[] args)

Prints out all the data. Give it one argument, N.