Important-Algorithms/Trie.java at main · AraragiSenpai7/Important-Algorithms · GitHub

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class Trie {

    class TrieNode {
        public TrieNode[] next;
        public boolean isWord;

        public TrieNode() {
            this.next = new TrieNode[26];
            this.isWord = false;
        }
    }

    private TrieNode root;

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

    public void insert(String word) {
        TrieNode node = root;
        for (char c : word.toCharArray()) {
            if (node.next[c - 'a'] == null) {
                node.next[c - 'a'] = new TrieNode();
            }
            node = node.next[c - 'a'];
        }
        node.isWord = true;
    }

    public boolean search(String word) {
        TrieNode node = root;
        for (char c : word.toCharArray()) {
            if (node.next[c - 'a'] == null) {
                return false;
            }
            node = node.next[c - 'a'];
        }
        return node.isWord;
    }

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