edu.princeton.cs.algs4

Class Alphabet

java.lang.Object

edu.princeton.cs.algs4.Alphabet

public class Alphabet
extends java.lang.Object

Field Summary

Fields

Modifier and Type	Field and Description
static Alphabet	ASCII The ASCII alphabet (0-127).
static Alphabet	BASE64 The base-64 alphabet (64 characters).
static Alphabet	BINARY The binary alphabet { 0, 1 }.
static Alphabet	DECIMAL The decimal alphabet { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }.
static Alphabet	DNA The DNA alphabet { A, C, T, G }.
static Alphabet	EXTENDED_ASCII The extended ASCII alphabet (0-255).
static Alphabet	HEXADECIMAL The hexadecimal alphabet { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F }.
static Alphabet	LOWERCASE The lowercase alphabet { a, b, c, ..., z }.
static Alphabet	OCTAL The octal alphabet { 0, 1, 2, 3, 4, 5, 6, 7 }.
static Alphabet	PROTEIN The protein alphabet { A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W, Y }.
static Alphabet	UNICODE16 The Unicode 16 alphabet (0-65,535).
static Alphabet	UPPERCASE The uppercase alphabet { A, B, C, ..., Z }.

Constructor Summary

Constructors

Constructor and Description
Alphabet() Initializes a new alphabet using characters 0 through 255.
Alphabet(java.lang.String alpha) Initializes a new alphabet from the given set of characters.

Method Summary

Modifier and Type	Method and Description
boolean	contains(char c) Returns true if the argument is a character in this alphabet.
int	lgR() Returns the binary logarithm of the number of characters in this alphabet.
static void	main(java.lang.String[] args) Unit tests the Alphabet data type.
int	R() Deprecated. Replaced by radix().
int	radix() Returns the number of characters in this alphabet (the radix).
char	toChar(int index) Returns the character corresponding to the argument index.
java.lang.String	toChars(int[] indices) Returns the characters corresponding to the argument indices.
int	toIndex(char c) Returns the index corresponding to the argument character.
int[]	toIndices(java.lang.String s) Returns the indices corresponding to the argument characters.

Methods inherited from class java.lang.Object

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

Field Detail

BINARY

public static final Alphabet BINARY

The binary alphabet { 0, 1 }.

OCTAL

public static final Alphabet OCTAL

The octal alphabet { 0, 1, 2, 3, 4, 5, 6, 7 }.

DECIMAL

public static final Alphabet DECIMAL

The decimal alphabet { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }.

HEXADECIMAL

public static final Alphabet HEXADECIMAL

The hexadecimal alphabet { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F }.

DNA

public static final Alphabet DNA

The DNA alphabet { A, C, T, G }.

LOWERCASE

public static final Alphabet LOWERCASE

The lowercase alphabet { a, b, c, ..., z }.

UPPERCASE

public static final Alphabet UPPERCASE

The uppercase alphabet { A, B, C, ..., Z }.

PROTEIN

public static final Alphabet PROTEIN

The protein alphabet { A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W, Y }.

BASE64

public static final Alphabet BASE64

The base-64 alphabet (64 characters).

ASCII

public static final Alphabet ASCII

The ASCII alphabet (0-127).

EXTENDED_ASCII

public static final Alphabet EXTENDED_ASCII

The extended ASCII alphabet (0-255).

UNICODE16

public static final Alphabet UNICODE16

The Unicode 16 alphabet (0-65,535).

Constructor Detail

Alphabet

public Alphabet(java.lang.String alpha)

Initializes a new alphabet from the given set of characters.

Parameters:

alpha - the set of characters

Alphabet

public Alphabet()

Initializes a new alphabet using characters 0 through 255.

Method Detail

contains

public boolean contains(char c)

Returns true if the argument is a character in this alphabet.

Parameters:

c - the character

Returns:

true if c is a character in this alphabet; false otherwise

R

@Deprecated
public int R()

Deprecated. Replaced by radix().

Returns the number of characters in this alphabet (the radix).

Returns:

the number of characters in this alphabet

radix

public int radix()

Returns the number of characters in this alphabet (the radix).

Returns:

the number of characters in this alphabet

lgR

public int lgR()

Returns the binary logarithm of the number of characters in this alphabet.

Returns:

the binary logarithm (rounded up) of the number of characters in this alphabet

toIndex

public int toIndex(char c)

Returns the index corresponding to the argument character.

Parameters:

c - the character

Returns:

the index corresponding to the character c

Throws:

java.lang.IllegalArgumentException - unless c is a character in this alphabet

toIndices

public int[] toIndices(java.lang.String s)

Returns the indices corresponding to the argument characters.

Parameters:

s - the characters

Returns:

the indices corresponding to the characters s

Throws:

java.lang.IllegalArgumentException - unless every character in s is a character in this alphabet

toChar

public char toChar(int index)

Returns the character corresponding to the argument index.

Parameters:

index - the index

Returns:

the character corresponding to the index index

Throws:

java.lang.IllegalArgumentException - unless 0 <= index < R

toChars

public java.lang.String toChars(int[] indices)

Returns the characters corresponding to the argument indices.

Parameters:

indices - the indices

Returns:

the characters corresponding to the indices indices

Throws:

java.lang.IllegalArgumentException - unless 0 < indices[i] < R for every i

main

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

Unit tests the Alphabet data type.

Parameters:

args - the command-line arguments