208. 实现 Trie (前缀树)

208. 实现 Trie (前缀树)

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题目链接：208. 实现 Trie (前缀树)

代码如下：

//参考leetcode官方题解
class Trie {
private:
    vector<Trie*> children;
    bool isEnd;

    Trie* searchPrefix(string prefix)
    {
        Trie* node=this;
        for(int i=0;i<prefix.size();i++)
        {
            if(!node->children[prefix[i]-'a'])
            {
                return nullptr;
            }
            node=node->children[prefix[i]-'a'];
        }
        return node;
    }

public:
    Trie():children(26),isEnd(false){}
    
    void insert(string word) 
    {
        Trie* node=this;
        for(int i=0;i<word.size();i++)
        {
            if(!node->children[word[i]-'a'])
            {
                node->children[word[i]-'a']=new Trie();
            }
            node=node->children[word[i]-'a'];
        }
        node->isEnd=true;
    }
    
    bool search(string word) 
    {
        Trie* node=searchPrefix(word);
        return node!=nullptr&&node->isEnd;
    }
    
    bool startsWith(string prefix) 
    {
        Trie* node=searchPrefix(prefix);
        return node!=nullptr;
    }
};

/**
 * Your Trie object will be instantiated and called as such:
 * Trie* obj = new Trie();
 * obj->insert(word);
 * bool param_2 = obj->search(word);
 * bool param_3 = obj->startsWith(prefix);
 */