Find Anagrams in a List

Question

So I have a question that's kinda weird.

I have a list of "Word" objects. A "Word" object contains one string, myCWord which is equal to the canonical version of a String passed into the Word.

For example:

Word one = new Word("cba");

one.getMyCWord(); // returns abc

Canonical form is the sorted characters in the String.

So now I have a list of words, where I can access the canonical version of the Strings they hold.

I need an algorithm to create "sub lists" which are lists of which contain a set of words which are anagrams of eachother.

So if I have:

List<AnagramSet> aSet = new LinkedList<AnagramSet>();
List<Word> words = new LinkedList<Word>();
words.add("ok"); // cword returns ko
words.add("abc"); // cword returns abc
words.add("cba"); // cword returns abc still

someMethod(words);

someMethod(List<Word> a) {
// build new sub lists

AnagramSet.add(new Anagram(temp));

}

How can I build the sublists correctly?

Lux · Answer 1 · 2014-11-26T03:50:00.003

1

This will cycle through all the words in wordlist and if they are anagrams, they are are placed in anagrams.

boolean isAnagram(Word word){
    if(word.myCWord() == word){
        return true;
    } else {
        return false;
    }
}

void anagramAlgorithm(List<Word> wordlist){
    List<Anagram> anagrams = new LinkedList<Anagram>();
    for(Word w : worldlist){
        if(isAnagram(w)) anagrams.add(new Anagram(w));
    }
    // Is this what you want?
    aSet.add(anagrams);
}

edited Nov 26 '14 at 03:50

answered Nov 26 '14 at 03:28

Lux

1,540
1
22
28

Close! But AnagramSet has to take a linked list of Anagrams :/ – Andrew Nov 26 '14 at 03:32

score 0 · Answer 2 · answered Nov 26 '14 at 03:07

Make a HashMap that maps canonical words to lists of words. Iterate over your words. For each word:

Is the canonical word a key in the map? If not, add it and associate an empty list with it.
Look up the list associated with the canonical word and add the actual word to it.

Find Anagrams in a List

2 Answers2