720. Longest Word in Dictionary

Input: 
words = ["w","wo","wor","worl", "world"]
Output: "world"
Explanation: 
The word "world" can be built one character at a time by "w", "wo", "wor", and "worl".

Input: 
words = ["a", "banana", "app", "appl", "ap", "apply", "apple"]
Output: "apple"
Explanation: 
Both "apply" and "apple" can be built from other words in the dictionary. However, "apple" is lexicographically smaller than "apply".

class Solution {
    public String longestWord(String[] words) {
        Map<Integer, String> hmap = new HashMap<>();
        int max = Integer.MIN_VALUE;
        
        for(String word : words){
            Set<Character> set = new HashSet<>();
            for(Character c : word.toCharArray()){
                set.add(c);
            }
            
            if(max <= set.size()){
                max = set.size();
                if(hmap.containsKey(max)){
                    if(word.compareTo(hmap.get(max)) > 0){
                        //hmap.remove(max);
                        hmap.put(max, word);
                    }
                }else{
                    hmap.put(max, word);
                }
            }
        }
        
        if(hmap.containsKey(max)){
            return hmap.get(max);
        }
        
        return "";
    }
}

[문제] https://leetcode.com/problems/longest-word-in-dictionary/