链接:https://leetcode-cn.com/problems/add-and-search-word-data-structure-design/
class WordDictionary {
private Node root;
public WordDictionary() {
root=new Node();
}
public void addWord(String word) {
Node cur=root;
for(int i=0;i<word.length();i++){
char c=word.charAt(i);
if(cur.next.get(c)==null){
cur.next.put(c, new Node());
}
cur=cur.next.get(c);
}
if(!cur.isWord){
cur.isWord=true;
}
}
public boolean search(String word) {
return match(root, word, 0);
}
private boolean match(Node node,String word,int index){
if(index==word.length()){
return node.isWord;
}
char c=word.charAt(index);
if(c!='.'){
if(node.next.get(c)==null){
return false;
}
return match(node.next.get(c), word, index+1);
}else{
for(char nextChar:node.next.keySet()){
if(match(node.next.get(nextChar), word, index+1)){
return true;
}
}
return false;
}
}
private class Node{
public boolean isWord;
public TreeMap<Character,Node> next;
public Node(boolean isWord){
this.isWord=isWord;
next=new TreeMap<Character, Node>();
}
public Node(){
this(false);
}
}
}