[leetcode]211. Add and Search Word

题目链接：https://leetcode.com/problems/add-and-search-word-data-structure-design/tabs/description

Design a data structure that supports the following two operations:

void addWord(word)bool search(word)

search(word) can search a literal word or a regular expression string containing only letters a-z or .. A . means it can represent any one letter.

For example:

addWord("bad")addWord("dad")addWord("mad")search("pad") -> falsesearch("bad") -> truesearch(".ad") -> truesearch("b..") -> true

class TrieNode{public:    bool isKey;    TrieNode* children[26];    TrieNode():isKey(false){        memset(children,NULL,sizeof(TrieNode*)*26);    };};class WordDictionary {public:    /** Initialize your data structure here. */    WordDictionary() {        root=new TrieNode();    }    /** Adds a word into the data structure. */    void addWord(string word) {        TrieNode* run=root;        for(char c:word)        {            if(!(run->children[c-'a']))                run->children[c-'a']=new TrieNode();            run=run->children[c-'a'];        }        run->isKey=true;    }    /** Returns if the word is in the data structure. A word could contain the dot character '.' to represent any one letter. */    bool search(string word) {        return query(word.c_str(),root);    }private:    TrieNode* root;    bool query(const char* word,TrieNode* node)    {        TrieNode* run=node;        for(int i=0;word[i];i++)        {            if(run && word[i]!='.')                run=run->children[word[i]-'a'];            else if(run && word[i]=='.')            {                TrieNode* tmp=run;                for(int j=0;j<26;j++)                {                    run=tmp->children[j];                    if(query(word+i+1,run))                        return true;                }            }            else                break;        }        return run && run->isKey;    }};