(Data structure)Implement Trie And Add and Search Word

class TrieNode {
    // Initialize your data structure here.
    boolean isEnd;
    TrieNode[] sons;
    char value;

    public TrieNode() {
        isEnd = false;
        sons = new TrieNode[26];
    }
}

public class Trie {
    private TrieNode root;

    public Trie() {
        root = new TrieNode();
    }

    // Inserts a word into the trie.
    public void insert(String word) {
        if (word == null || word.length() == 0)
            return;
        TrieNode p = root;
        for (int i = 0; i < word.length(); i++) {
            int pos = word.charAt(i) - ‘a‘;
            if (p.sons[pos] == null) {
                p.sons[pos] = new TrieNode();
                p.sons[pos].value = word.charAt(i);
            }
            p = p.sons[pos];
        }
        p.isEnd = true;
    }

    // Returns if the word is in the trie.
    public boolean search(String word) {
        if (word == null || word.length() == 0)
            return false;
        TrieNode p = root;
        for (int i = 0; i < word.length(); i++) {
            int pos = word.charAt(i) - ‘a‘;
            if (p.sons[pos] == null)
                return false;
            p = p.sons[pos];
        }
        return p.isEnd;
    }

    // Returns if there is any word in the trie
    // that starts with the given prefix.
    public boolean startsWith(String prefix) {
        if (prefix == null || prefix.length() == 0)
            return false;
        TrieNode p = root;
        for (int i = 0; i < prefix.length(); i++) {
            int pos = prefix.charAt(i) - ‘a‘;
            if (p.sons[pos] == null)
                return false;
            p = p.sons[pos];
        }
        return true;
    }
}

// Your Trie object will be instantiated and called as such:
// Trie trie = new Trie();
// trie.insert("somestring");
// trie.search("key");

public class WordDictionary {

    private Tode root;
    
    public WordDictionary() {
        root = new Tode();
    }
    
    // Adds a word into the data structure.
    public void addWord(String word) {
        if(word == null || word.length() == 0)
            return ;
        Tode p = root;
        for(int i=0; i<word.length(); i++){
            int pos = word.charAt(i) - ‘a‘;
            if(p.sons[pos] == null){
                p.sons[pos] = new Tode();
                p.sons[pos].value = word.charAt(i);
            }
            p = p.sons[pos];
        }    
        p.isEnd = true;    
    }

    // Returns if the word is in the data structure. A word could
    // contain the dot character ‘.‘ to represent any one letter.
    public boolean search(String word) {
        if(word == null || word.length() == 0)
            return false;
        char[] arr = word.toCharArray();
        int index = 0;
        Tode p = root;
        return goSearch(arr, index, p);
    }

    private boolean goSearch(char[] arr, int index, Tode p) {
        if(index == arr.length)
            return p.isEnd;
        if(arr[index] == ‘.‘){
            for(Tode n : p.sons){
                if(n != null && goSearch(arr, index+1, n))
                    return true;
            }
            return false;
        }else{
            int pos = arr[index] - ‘a‘;
            if(p.sons[pos] != null)
                return goSearch(arr, index+1, p.sons[pos]);
            else
                return false;
        }
    }

    class Tode{
        boolean isEnd;
        Tode[] sons;
        char value;
        public Tode(){
            isEnd = false;
            sons = new Tode[26];
        }
    }
}

// Your WordDictionary object will be instantiated and called as such:
// WordDictionary wordDictionary = new WordDictionary();
// wordDictionary.addWord("word");
// wordDictionary.search("pattern");