package com.hit.basmath.learn.hash_table;

import java.util.*;

/**
 * 49. Group Anagrams
 * <p>
 * Given an array of strings, group anagrams together.
 * <p>
 * Example:
 * <p>
 * Input: ["eat", "tea", "tan", "ate", "nat", "bat"],
 * <p>
 * Output:
 * <p>
 * [
 * ["ate","eat","tea"],
 * ["nat","tan"],
 * ["bat"]
 * ]
 * <p>
 * Note:
 * <p>
 * All inputs will be in lowercase.
 * The order of your output does not matter.
 */
public class _49 {
    public List<List<String>> groupAnagrams(String[] strs) {
        if (strs == null || strs.length == 0) return new ArrayList<>();
        Map<String, List<String>> map = new HashMap<String, List<String>>();
        for (String s : strs) {
            char[] ca = s.toCharArray();
            Arrays.sort(ca);
            String keyStr = String.valueOf(ca);
            if (!map.containsKey(keyStr)) {
                map.put(keyStr, new ArrayList<>());
            }
            map.get(keyStr).add(s);
        }
        return new ArrayList<>(map.values());
    }
}