LeetCode- Implement Trie (Prefix Tree)

Implement a trie with insert, search, and startsWith methods.

Note:
You may assume that all inputs are consist of lowercase letters a-z.

Solution:

class TrieNode {
    TrieNode[] childs;
    boolean hasWords;
    
    // Initialize your data structure here.
    public TrieNode() {
        childs = new TrieNode[26];
        hasWords = false;
    }
}

public class Trie {
    private TrieNode root;

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

    // Inserts a word into the trie.
    public void insert(String word) {
        TrieNode cur = root;
        for (int i=0;i<word.length();i++){
            char curChar = word.charAt(i);
            if (cur.childs[curChar-'a']==null){
                cur.childs[curChar-'a'] = new TrieNode();
            } 
            cur = cur.childs[curChar-'a'];
        }
        cur.hasWords = true;
    }

    // Returns if the word is in the trie.
    public boolean search(String word) {
        TrieNode cur = root;
        for (int i=0;i<word.length();i++){
            char curChar = word.charAt(i);
            if (cur.childs[curChar-'a']==null){
                return false;
            }
            cur = cur.childs[curChar-'a'];
        }
        return cur.hasWords;
    }

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

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