Class WordGamesUtil

java.lang.Object

WordGamesUtil

public class WordGamesUtil
extends Object

A utility class containing methods related to word games.

Author:

EECS1030_W15

Field Summary

Fields

Modifier and Type	Field and Description
static Dictionary	DICTIONARY A dictionary of lower case English words.

Method Summary

Methods

Modifier and Type	Method and Description
static SortedSet<String>	allAdjacentTo(String s) Returns a sorted set of all words in WordGamesUtil.DICTIONARY that are adjacent to the string s.
static SortedSet<String>	allAdjacentTo(String s, int index) Returns a sorted set of all words in WordGamesUtil.DICTIONARY that are adjacent to the string s and differ from s exactly at the given index.
static boolean	areAdjacent(String s, String t) Determines if two strings are adjacent words.
static int	distance(String s, String t) Returns the Hamming distance between two strings.

Methods inherited from class java.lang.Object

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

Field Detail

DICTIONARY

public static final Dictionary DICTIONARY

A dictionary of lower case English words. The dictionary cannot be modified.

Method Detail

distance

public static int distance(String s,
           String t)

Returns the Hamming distance between two strings. The Hamming distance is the number of indices where the characters in two strings are different.

Throws:

IllegalArgumentException - if s.length() != t.length()

Parameters:

s - a string

t - a string

Returns:

the Hamming distance between s and t

areAdjacent

public static boolean areAdjacent(String s,
                  String t)

Determines if two strings are adjacent words. The string s is adjacent to t if and only if all of the following conditions are true:

• the string s is in WordGamesUtil.DICTIONARY
• the string t is in WordGamesUtil.DICTIONARY
• the string s is the same length as t
• s and t are identical except in exactly one position

Parameters:

s - a string

t - a string

Returns:

true if s and t are adjacent, false otherwise

allAdjacentTo

public static SortedSet<String> allAdjacentTo(String s)

Returns a sorted set of all words in WordGamesUtil.DICTIONARY that are adjacent to the string s. The sorting of the elements of the set is lexicographical (dictionary order).

Parameters:

s - a string

Returns:

a sorted set of words in WordGamesUtil.DICTIONARY that are adjacent to s

allAdjacentTo

public static SortedSet<String> allAdjacentTo(String s,
                              int index)

Returns a sorted set of all words in WordGamesUtil.DICTIONARY that are adjacent to the string s and differ from s exactly at the given index. The sorting of the elements of the set is lexicographical (dictionary order).

For example, suppose that we want to find all words that can be formed by changing the 't' in "cat". alldjacentTo("cat", 2) returns the set containing the strings "cab", "cad", "cam", "can", "cap", "car", "caw", "cay".

Parameters:

s - a string

index - the index where the adjacent words differ from s

Precondition:

index >= 0 && index < s.length()

Returns:

a sorted set of words in WordGamesUtil.DICTIONARY that are adjacent to s and differ from s exactly at the given index