Design a data structure that supports the following two operations: addWord(word) and 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.
Notice
You may assume that all words are consist of lowercase letters a-z.
Example
addWord("bad")
addWord("dad")
addWord("mad")
search("pad") // return false
search("bad") // return true
search(".ad") // return true
search("b..") // return true
LeetCode上的原题，请参见我之前的博客Add and Search Word - Data structure design。
class WordDictionary { public: struct TrieNode { bool isLeaf; TrieNode *child[26]; }; WordDictionary() { root = new TrieNode(); } // Adds a word into the data structure. void addWord(string word) { TrieNode *p = root; for (char c : word) { int i = c - 'a'; if (!p->child[i]) p->child[i] = new TrieNode(); p = p->child[i]; } p->isLeaf = 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) { search(word, root, 0); } bool search(string &word, TrieNode *p, int i) { if (i == word.size()) return p->isLeaf; if (word[i] == '.') { for (auto a : p->child) { if (a && search(word, a, i + 1)) return true; } return false; } else { return p->child[word[i] - 'a'] && search(word, p->child[word[i] - 'a'], i + 1); } } private: TrieNode *root; };
本文转自博客园Grandyang的博客，原文链接：添加和查找单词[LintCode] Add and Search Word ，如需转载请自行联系原博主。
