Wagner Fischer algorithm for spell checkers / autocorrects

wagner-fischer.java

// Credits : @b001io on github
// Repo link : https://github.com/b001io/wagner-fischer/blob/main/wagner_fischer.py

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class Main {

    public static List<String> loadDictionary(String filePath) throws IOException {
        List<String> dictionary = new ArrayList<>();
        BufferedReader reader = new BufferedReader(new FileReader(filePath));
        String line;
        while ((line = reader.readLine()) != null) {
            dictionary.add(line.trim());
        }
        reader.close();
        return dictionary;
    }

    public static int wagnerFischer(String s1, String s2) {
        int len_s1 = s1.length();
        int len_s2 = s2.length();
        if (len_s1 > len_s2) {
            String temp = s1;
            s1 = s2;
            s2 = temp;
            int tempLen = len_s1;
            len_s1 = len_s2;
            len_s2 = tempLen;
        }

        int[] currentRow = new int[len_s1 + 1];
        for (int i = 0; i <= len_s1; i++) {
            currentRow[i] = i;
        }

        for (int i = 1; i <= len_s2; i++) {
            int[] previousRow = currentRow.clone();
            currentRow[0] = i;
            for (int j = 1; j <= len_s1; j++) {
                int add = previousRow[j] + 1;
                int delete = currentRow[j - 1] + 1;
                int change = previousRow[j - 1] + (s1.charAt(j - 1) != s2.charAt(i - 1) ? 1 : 0);
                currentRow[j] = Math.min(Math.min(add, delete), change);
            }
        }

        return currentRow[len_s1];
    }

    public static List<Pair<String, Integer>> spellCheck(String word, List<String> dictionary) {
        List<Pair<String, Integer>> suggestions = new ArrayList<>();

        for (String correctWord : dictionary) {
            int distance = wagnerFischer(word, correctWord);
            suggestions.add(new Pair<>(correctWord, distance));
        }

        suggestions.sort((p1, p2) -> Integer.compare(p1.getValue(), p2.getValue()));
        return suggestions.subList(0, Math.min(10, suggestions.size()));
    }

    public static void main(String[] args) throws IOException {
        List<String> dictionary = loadDictionary("words.txt");
        String misspelledWord = "wrlod";
        List<Pair<String, Integer>> suggestions = spellCheck(misspelledWord, dictionary);
        System.out.println("Top 10 suggestions for '" + misspelledWord + "':");
        for (Pair<String, Integer> pair : suggestions) {
            System.out.println(pair.getKey() + " (Distance: " + pair.getValue() + ")");
        }
    }

    static class Pair<K, V> {
        private final K key;
        private final V value;

        public Pair(K key, V value) {
            this.key = key;
            this.value = value;
        }

        public K getKey() {
            return key;
        }

        public V getValue() {
            return value;
        }
    }
}