leetcode Implement Trie (Prefix Tree)
题目连接
https://leetcode.com/problems/implement-trie-prefix-tree/
Implement Trie (Prefix Tree)
Description
Implement a trie with insert, search, and startsWith methods.
字典树。。
class TrieNode { public: // Initialize your data structure here. bool vis; TrieNode *ch[26]; TrieNode() { vis = false; for (int i = 0; i < 26; i++) ch[i] = NULL; } }; class Trie { public: Trie() { root = new TrieNode(); } // Inserts a word into the trie. void insert(string word) { if (word.empty()) return; TrieNode *x = root; int d = 0; Ite p = word.begin(); while (p != word.end()) { d = *p - 'a'; if (!x->ch[d]) x->ch[d] = new TrieNode; x = x->ch[d]; p++; } x->vis = true; } // Returns if the word is in the trie. bool search(string word) { TrieNode *x = root; int d = 0; Ite p = word.begin(); while (p != word.end()) { d = *p - 'a'; if (!x || !x->ch[d]) return false; x = x->ch[d]; p++; } return x->vis; } // Returns if there is any word in the trie // that starts with the given prefix. bool startsWith(string prefix) { TrieNode *x = root; int d = 0; Ite p = prefix.begin(); while (p != prefix.end()) { d = *p - 'a'; if (!x || !x->ch[d]) return false; x = x->ch[d]; p++; } return x != NULL; } private: TrieNode* root; typedef string::iterator Ite; };
By: GadyPu 博客地址:http://www.cnblogs.com/GadyPu/ 转载请说明