Leetcode练习(Python)：回溯算法类：第211题：添加与搜索单词

题目：

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。 

思路：

尝试了很长时间的回溯方式，但是一直无法出来结果。第一感觉是不用回溯，直接使用比较的方式来做，程序1使用的是常规方法，之后补充回溯方法的程序。

程序1：常规方法

class WordDictionary:
    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.myDict = {}

    def addWord(self, word: str) -> None:
        """
        Adds a word into the data structure.
        """
        length = len(word)
        if length in self.myDict:
            self.myDict[length] += [word]
        else:
            self.myDict[length] = [word]
            
    def search(self, word: str) -> bool:
        """
        Returns if the word is in the data structure. A word could contain the dot character '.' to represent any one letter.
        """
        length = len(word)
        if length in self.myDict:
            for auxiliary in self.myDict[length]:
                index = 0
                for index1 in range(length):
                    if word[index1] != auxiliary[index1] and word[index1] != '.':
                        break
                    elif word[index1] == auxiliary[index1] or word[index1] == '.':
                        index += 1
                if index == length:
                    return True
        if length not in self.myDict:
            return False
        return False

# Your WordDictionary object will be instantiated and called as such:
# obj = WordDictionary()
# obj.addWord(word)
# param_2 = obj.search(word)