_320.java

package com.fishercoder.solutions;

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

/**
 * 320. Generalized Abbreviation
 *
 * Write a function to generate the generalized abbreviations of a word.

 Example:

 Given word = "word", return the following list (order does not matter):
 ["word", "1ord", "w1rd", "wo1d", "wor1", "2rd", "w2d", "wo2", "1o1d", "1or1", "w1r1", "1o2", "2r1", "3d", "w3", "4"]
 */
public class _320 {

    public static class Solution1 {
        public List<String> generateAbbreviations(String word) {
            List<String> result = new ArrayList<>();
            backtrack(word, result, 0, "", 0);
            return result;
        }

        private void backtrack(String word, List<String> result, int position, String current,
            int count) {
            if (position == word.length()) {
                if (count > 0) {
                    current += count;
                }
                result.add(current);
            } else {
                backtrack(word, result, position + 1, current, count + 1);
                backtrack(word, result, position + 1,
                    current + (count > 0 ? count : "") + word.charAt(position), 0);
            }
        }
    }

}