211. 添加与搜索单词 - 数据结构设计trie数的基本操作

Posted 2021-11-06 幽殇默

https://leetcode-cn.com/problems/design-add-and-search-words-data-structure/

class WordDictionary {
public:

    const static int N=50010;
    int son[N][30];
    int st[N];
    int idx;

    WordDictionary() 
    {
        idx=0;
        memset(son,0,sizeof son);
        memset(st,0,sizeof st);
    }
    
    void addWord(string word) {
        int p=0;
        for(int i=0;i<word.size();i++)
        {
            int u=word[i]-'a';
            if(!son[p][u]) son[p][u]=++idx;
            p=son[p][u];
        }
        st[p]=true;
    }
    
    bool search(string word) 
    {
        return dfs(0,word,0);
    }
    bool dfs(int p, string word, int i) 
    {
        if (i == word.size()) return st[p];
        else
         {
            if (word[i] != '.') 
            {
                int u = word[i] - 'a';
                if (!son[p][u]) return false;
                return dfs(son[p][u], word, i + 1);
            } else 
            {
                for (int j = 0; j < 26; j ++)
                    if (son[p][j] && dfs(son[p][j], word, i + 1)) return true;
                return false;
            }
        }
    }
};
/**
 * Your WordDictionary object will be instantiated and called as such:
 * WordDictionary* obj = new WordDictionary();
 * obj->addWord(word);
 * bool param_2 = obj->search(word);
 */