leetcode:Implement Trie (Prefix Tree)

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Implement a trie with insert, search, and startsWith methods.

Note:
You may assume that all inputs are consist of lowercase letters a-z.

class TrieNode {    public:    TrieNode *nodeMap[26];    int endNum;    public:    // Initialize your data structure here.    TrieNode() {        for (int i=0; i<26; i++)            nodeMap[i] = NULL;                    endNum = 0;    }};class Trie {    public:    Trie() {        root = new TrieNode();    }    // Inserts a word into the trie.    void insert(string word) {                TrieNode *curNode = root;                for (int i=0; i<word.size(); i++)        {            int wordIdx = word[i]-'a';                        if (curNode->nodeMap[wordIdx] == NULL)            {                TrieNode *newNode = new TrieNode();                curNode->nodeMap[wordIdx] = newNode;            }                        curNode = curNode->nodeMap[wordIdx];        }        curNode->endNum++;            }    // Returns if the word is in the trie.    bool search(string word) {        TrieNode *curNode = root;                for (int i=0; i<word.size(); i++)        {            int wordIdx = word[i]-'a';                        if (curNode->nodeMap[wordIdx] == NULL)                return false;            curNode = curNode->nodeMap[wordIdx];        }                if (curNode->endNum)            return true;                    return false;    }    // Returns if there is any word in the trie    // that starts with the given prefix.    bool startsWith(string prefix) {        TrieNode *curNode = root;                for (int i=0; i<prefix.size(); i++)        {            int wordIdx = prefix[i]-'a';                        if (curNode->nodeMap[wordIdx] == NULL)                return false;                            curNode = curNode->nodeMap[wordIdx];        }                return true;            }private:    TrieNode* root;};// Your Trie object will be instantiated and called as such:// Trie trie;// trie.insert("somestring");// trie.search("key");

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