208.Implement Trie(prefix-tree)

class Trie {
  
    static class TrieNode {
        TrieNode[] children;
        boolean isEndOfWord;

       
        TrieNode() {
            children = new TrieNode[26]; 
            isEndOfWord = false;
        }
    }

    private TrieNode root=new TrieNode();
    public Trie() {
   
    }
    public void insert(String word) {
        TrieNode node = root;
        for(char c:word.toCharArray()){
            int index=c-'a';
            if(node.children[index]==null){
                node.children[index]=new TrieNode();
            }
             node=node.children[index];
        }
        node.isEndOfWord=true;
    }

    public boolean search(String word) {
      TrieNode node=root;
      for(char c:word.toCharArray()){
        int index=c-'a';
        if(node.children[index]==null){
            return false;
        }
        node=node.children[index];
      }
      return node.isEndOfWord;
    }
    public boolean startsWith(String prefix) {
        TrieNode node=root;
        for(char c:prefix.toCharArray()){
            int index=c-'a';
            if(node.children[index]==null){
                return false;
            }
            node=node.children[index];
        }
        return true;
    }
}