(LEETCODE)DesignAddAndSearchWordsDS.cpp

class WordDictionary {
    vector<WordDictionary*> children;
    bool isEndOfWord;
public:
    /** Initialize your data structure here. */
    WordDictionary(): isEndOfWord(false) {
        children=vector<WordDictionary*>(26,nullptr);
    }
    
    /** Adds a word into the data structure. */
    void addWord(string word) {
        WordDictionary *curr  = this;
        for(char c:word){
            if(curr->children[c-'a'] == nullptr){
                curr->children[c-'a'] = new WordDictionary();
            }
            curr = curr->children[c-'a'];
        }
        curr->isEndOfWord =true;
    }

    /** Returns if the word is in the data structure. A word could contain the dot character '.' to represent any one letter. */
    bool search(string word) {
         WordDictionary *curr  = this;
        for(int i=0;i<word.length();++i){
            char c= word[i];
            if(c=='.'){
                for(auto ch:curr->children){
                    if(ch && ch->search(word.substr(i+1))) return true;
                }
                return false;
            }
            
            if(curr->children[c-'a']==nullptr) return false;
            curr=curr->children[c-'a'];
        }
        return curr && curr->isEndOfWord;
    }
};

/**
 * Your WordDictionary object will be instantiated and called as such:
 * WordDictionary* obj = new WordDictionary();
 * obj->addWord(word);
 * bool param_2 = obj->search(word);
 */