Design a data structure that supports adding new words and finding if a string matches any previously added string.
Implement the WordDictionary class:
WordDictionary() Initializes the object.
void addWord(word) Adds word to the data structure, it can be matched later.
bool search(word) Returns true if there is any string in the data structure that matches word or false otherwise. word may contain dots '.' where dots can be matched with any letter.
class WordDictionary {
private WordDictionary[] children;
boolean isEndOfWord;
public WordDictionary() {
children = new WordDictionary[26];
isEndOfWord = false;
}
public void addWord(String word) {
WordDictionary curr = this;
for(char c: word.toCharArray()){
if(curr.children[c - 'a'] == null)
curr.children[c - 'a'] = new WordDictionary();
curr = curr.children[c - 'a'];
}
curr.isEndOfWord = true;
}
public boolean search(String word) {
WordDictionary curr = this;
for(int i = 0; i < word.length(); ++i){
char c = word.charAt(i);
if(c == '.'){
for(WordDictionary ch: curr.children)
if(ch != null && ch.search(word.substring(i+1))) return true;
return false;
}
if(curr.children[c - 'a'] == null) return false;
curr = curr.children[c - 'a'];
}
return curr != null && curr.isEndOfWord;
}
}
