如何通过在相邻字符之间添加空格将一个单词分为两个单词

Question

I am trying to take the word: missspelling and split the word into two words by adding a " " (space) between adjacent chars and want to get the word: miss spelling as a result. Any guidance would help, been trying out different code, but have not seen results.

Code that works for other suggestions for reference only. *Note that commented out code is what I have been messing with to try and get the correct result.

    /**
     * Returns possible suggestions for misspelled word
     * 
     * @param tree The Trie that will be checked
     * @param word The word in trie that is checked
     */
    public static void suggest(TrieNode tree, String word) {
        Set<String> result = new HashSet<>();
        System.out.println("Suggestions: ");
        // Remove a character
        for (int i = 0; i < word.length(); ++i)
            result.add(word.substring(0, i) + word.substring(i + 1));
        // Swap two consecutive characters
        for (int i = 0; i < word.length() - 1; ++i)
            result.add(word.substring(0, i) + word.substring(i + 1, i + 2) + word.substring(i, i + 1)
                    + word.substring(i + 2));
        // Replace a character with other
        for (int i = 0; i < word.length(); ++i)
            for (char c = 'a'; c <= 'z'; ++c)
                result.add(word.substring(0, i) + String.valueOf(c) + word.substring(i + 1));
        // Add a new character
        for (int i = 0; i <= word.length(); ++i)
            for (char c = 'a'; c <= 'z'; ++c)
                result.add(word.substring(0, i) + String.valueOf(c) + word.substring(i));
        // Split word into pair of words by adding a " " between adjacent pairs
        // Need help here
        for (int i = 0; i < word.length(); ++i)
            for (char c = ' '; c <= ' '; ++c)
                if (search(tree, word.substring(0, i)) && search(tree, word.substring(i)) == true)
                     result.add(word.substring(0, i) + String.valueOf(c) + word.substring(i));


        ArrayList<String> res = new ArrayList<>(result);
        int j = 0;
        for (int i = 0; i < result.size(); i++)
            if (search(tree, res.get(i))) {
                if (j == 0)
                    System.out.print("[");
                System.out.print(res.get(i) + ",");
                System.out.print("");
                j++;
            }
         System.out.print("]" + "\n");
    }

Answer 1

I wrote a minimal, runnable piece of code that splits words if the two word pieces are found in the dictionary.

Here are my test results

miss spelling
apple

And here's the code. The important method is the splitWord method.

package com.ggl.testing;

import java.util.ArrayList;
import java.util.List;

public class DoubleWord implements Runnable {

    public static void main(String[] args) {
        new DoubleWord().run();
    }

    @Override
    public void run() {
        Dictionary dictionary = new Dictionary();
        System.out.println(splitWord("missspelling", dictionary));
        System.out.println(splitWord("apple", dictionary));
    }

    public String splitWord(String word, Dictionary dictionary) {
        for (int index = 1; index < word.length(); index++) {
            String prefix = word.substring(0, index);
            if (dictionary.isWordInDictionary(prefix)) {
                String suffix = word.substring(index);
                if (dictionary.isWordInDictionary(suffix)) {
                    return prefix + " " + suffix;
                }
            }
        }

        return word;
    }

    public class Dictionary {
        private List<String> words;

        public Dictionary() {
            this.words = setWords();
        }

        public boolean isWordInDictionary(String word) {
            return words.contains(word);
        }

        private List<String> setWords() {
            List<String> words = new ArrayList<>();
            words.add("apple");
            words.add("miss");
            words.add("spelling");
            words.add("zebra");

            return words;
        }
    }

}

Answer 2

A couple of things first...

This line is insane:

for (char c = ' '; c <= ' '; ++c)

It will iterate exactly once and is equivalent to:

char c = ' ';

---

You are reinventing the wheel by attempting to find valid words by swapping chars and then by substituting chars: Read about Levenshtein distance , implement that algorithm, then sort your dictionary by the Levenshtein distance from your input to find "best matches", which should be filtered by a maximum Levenshtein distance - perhaps 3 would be a good starting point (test your code and see if the result is reasonable).

---

Your TrieNode should have a search() method, rather than your search() method accepting a trie and a word, but that's more a matter of design and isn't your biggest problem.

---

Now then, regarding your actual question, attempting to split the input is complicated, but the "answer" is:

Loop through all positions in the input between letters, and put each "half" through the same process as your input, except that you should not do a nested split, combining every combination of suggestions for each half, then return a collection of all unique suggestion combniations .

However, doing this this will result is a "very large" number of suggestions and thus will not scale, so you probably shouldn't do it.