Method getLast

java/0208-implement-trie-prefix-tree.java:26–36

(String word)

    //helper method
    public Node getLast(String word) {
        Node curr = root;
        for (char x : word.toCharArray()) {
            if (curr.children[x - 'a'] == null) {
                return null;
            }

            curr = curr.children[x - 'a'];
        }
        return curr;
    }

    public boolean startsWith(String prefix) {
        Node res = getLast(prefix);