0819. Most Common Word #

class Solution {
    public String mostCommonWord (String paragraph, String[] banned) {
        Set<String> set = new HashSet<>();
        for (String ban: banned) set.add(ban);
        
        Map<String, Integer> map = new HashMap<>();
        int maxCnt = 0;
        String maxWord = "";
        
        Character[] punctuations = new Character[]{'!', '?', '\'', ',', ';', '.'};
        for (Character punctuation: punctuations) paragraph = paragraph.replace(puctuation, ' ');
        String[] words = paragraph.split(" ");
        for (int i = 0; i < words.length; i++) {
            String word = words[i].toLowerCase();
            if (word != "" && set.contains(word) == false) {
                map.put(word, map.getOrDefault(word, 0) + 1);
                if (map.get(word) > maxCnt) {
                    maxCnt = map.get(word);
                    maxWord = word;
                }
            }
        }
        
        return maxWord;
    }
}