java刷题--208Trie前缀树

Posted 2022-12-13 Anrys

java刷题--208Trie前缀树

• 题目
• 代码
• 结果

题目

腾讯二面–所以说知识点一定要全

代码

class Trie 
    private Trie[] children;
    private boolean isEnd;
    public Trie() 
        children = new Trie[26];
        isEnd = false;
    
    public void insert(String word) 
        Trie node = this;
        for (int i = 0; i < word.length(); i++) 
            char ch = word.charAt(i);
            int index = ch - 'a';
            if (node.children[index] == null) 
                node.children[index] = new Trie();
            node = node.children[index];
        node.isEnd = true;
     
    public boolean search(String word) 
        Trie node = searchPrefix(word);
        return node != null && node.isEnd;
    
    public boolean startsWith(String prefix) return searchPrefix(prefix) != null;
    private Trie searchPrefix(String prefix) 
        Trie node = this;
        for (int i = 0; i < prefix.length(); i++) 
            char ch = prefix.charAt(i);
            int index = ch - 'a';
            if (node.children[index] == null) return null;
            node = node.children[index];
        return node;
    

结果