LeetCode-211. 添加与搜索单词 - 数据结构设计

设计一个支持以下两种操作的数据结构：

void addWord(word)
bool search(word)
search(word) 可以搜索文字或正则表达式字符串，字符串只包含字母 . 或 a-z 。 . 可以表示任何一个字母。

示例:

addWord("bad")
addWord("dad")
addWord("mad")
search("pad") -> false
search("bad") -> true
search(".ad") -> true
search("b..") -> true
说明:

你可以假设所有单词都是由小写字母 a-z 组成的。

思路就是，字典树，加DFS递归，一定注意递归退出条件，我因为退出条件的部分没想明白，

把自己绕进死胡同，耗费大量时间了。

#include <iostream>
#include <string.h>
#include <vector>
#include <set>
using namespace std;
class WordDictionary {

private:
    int MaxWordLen;
    int MinWordLen;
    int CurWordLen;
    WordDictionary* next[26];
    bool isEnd;

public:
    /** Initialize your data structure here. */
    WordDictionary() {
        MaxWordLen = 0;
        MinWordLen = INT_MAX;
        CurWordLen = 0;
        memset(next,0x00,sizeof(next));
        isEnd = false;
    }

    /** Adds a word into the data structure. */
    void addWord(string word) {
        if(word.length()==0)
            return;

        if(word.length()>MaxWordLen)
            MaxWordLen = word.length();
        if(word.length()<MinWordLen)
            MinWordLen = word.length();

        WordDictionary *node = this;
        for(char c:word){
            if(node->next[c-'a']==NULL){
                node->next[c-'a'] = new WordDictionary();
            }
            node = node->next[c-'a'];
        }
        node->isEnd = 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) {
        if(word.length()>MaxWordLen || word.length()<MinWordLen){
            return false;
        }
        CurWordLen = word.length();
        const char *charArry =word.c_str();
        //printf("[%s]\n",charArry);
        WordDictionary *node = this;
        return IsLegalTo(node,charArry,0);
    }

    bool IsLegalTo(WordDictionary *node,const char*arr, int index){
        //        cout<<"arr:"<<arr[index]<<"----index:"<<index<<"---CurWordLen:"<<CurWordLen<<endl;

        if(node==NULL){
            return false;
        }

        if(index==CurWordLen){
            //cout<<"node->isEnd:"<<node->isEnd<<endl;
            return node->isEnd;
        }

        if(arr[index]=='.'){
            for(int i=0;i<26;i++){
                if(IsLegalTo(node->next[i],arr,index+1)){
                    return true;
                }
            }
            //cout<<"get in this"<<endl;
            return false;
        }else{
            char c = arr[index];
            if(node->next[c-'a']==NULL){
                //cout<<"char:"<<arr[index]<<"--index:"<<index<<endl;
                return false;
            }
            else{
                node =node->next[c-'a'];
                return IsLegalTo(node,arr,index+1);
            }
        }
        return false;
    }
};

int main(){
    WordDictionary *pw = new WordDictionary();

    //test case 1
    //    pw->addWord("a");
    //    pw->addWord("ab");
    //    cout<<"main:"<<pw->search("a")<<endl;
    //    cout<<"main:"<<pw->search("a.")<<endl;
    //    cout<<"main:"<<pw->search("ab")<<endl;
    //    cout<<"main:"<<pw->search(".a")<<endl;
    //    cout<<"main:"<<pw->search(".b")<<endl;
    //    cout<<"main:"<<pw->search("ab.")<<endl;
    //    cout<<"main:"<<pw->search(".")<<endl;
    //    cout<<"main:"<<pw->search("..")<<endl;

    //test case 2
    pw->addWord("bad");
    pw->addWord("dad");
    pw->addWord("mad");
    cout<<pw->search("pad")<<endl;
    cout<<pw->search("bad")<<endl;
    cout<<pw->search(".ad")<<endl;
    cout<<pw->search("b..")<<endl;

    // test case 3
    //    pw->addWord("at");
    //    pw->addWord("and");
    //    pw->addWord("an");
    //    pw->addWord("add");

    //    cout<<"main:"<<pw->search("a")<<endl;
    //    cout<<"main:"<<pw->search(".at")<<endl;
    //    pw->addWord("bat");
    //    cout<<"addword(bat)++++++++++++++++++++"<<endl;
    //    cout<<"main:"<<pw->search(".at")<<endl;
    //    cout<<"main:"<<pw->search("an.")<<endl;
    //    cout<<"main:"<<pw->search("a.d.")<<endl;
    //    cout<<"main:"<<pw->search("b.")<<endl;
    //    cout<<"main:"<<pw->search("a.d")<<endl;
    //    cout<<"main:"<<pw->search(".")<<endl;


    // test case 4
    //    pw->addWord("ran");
    //    pw->addWord("rune");
    //    pw->addWord("runner");
    //    pw->addWord("runs");
    //    pw->addWord("add");
    //    pw->addWord("adds");
    //    pw->addWord("adder");
    //    pw->addWord("addee");
    //    cout<<"main:"<<pw->search("....e.")<<endl;


    // test case 4
    //    pw->addWord("ran");
    //    pw->addWord("rune");
    //    pw->addWord("runner");
    //    pw->addWord("runs");
    //    pw->addWord("add");
    //    pw->addWord("adds");
    //    pw->addWord("adder");
    //    pw->addWord("addee");

    //   cout<<"main:"<<pw->search(".an.")<<endl;


    return 0;
}