字典树的使用（匹配子串）

class Substr {

private:
    struct TrieNode {
        char sz;
        bool flag;
        TrieNode* child[26];

        TrieNode():sz(0),flag(false)
        {
            for (size_t i = 0; i < 26; i++)
            {
                child[i] = NULL;
            }
        }

        ~TrieNode()
        {
            for (size_t i = 0; i < 26; i++)
            {
                if (NULL != child[i]) {
                    delete child[i];
                    child[i] = NULL;
                }
            }
        }
    };

    void insert(const string& str,const int& left,const int& right, TrieNode* root) {
        int index = str[left] - ‘a‘;
        if (root->child[index] == NULL) {
            root->child[index] = new TrieNode;
            memset(root->child[index], 0, sizeof(TrieNode));
            root->child[index]->sz = str[left];
        }

        if (left==right)
        {
            root->child[index]->flag = true; 
            return;
        }
        else
        {
            insert(str,left+1,right, root->child[index]);
        }
    }

    void build_TrieNode(const string& str, TrieNode* root)
    {
        int len = str.length(),left,right;
        if (len==0)
            return;

        left = 0;right = len - 1;
        for (; left <= right; left++)
        {
            insert(str, left, right, root);
        }
    }

    bool comparestr(TrieNode* root, const string& str)
    {
        int num = 0, len = str.length(), index;
        if (NULL == root || len <= 0) return false;
        TrieNode* p = root;

        while (p&&num < len)
        {
            index = str[num] - ‘a‘;
            if (p->child[index])
            {
                ++num;
            }
            p = p->child[index];
        }

        if (num == len)
            return true;
        else return false;
    }

public:
    vector<bool> chkSubStr(vector<string> p, int n, string s) {

        vector<bool> res;
        int i, len = p.size(), strlen = s.length();
        if (len <= 0 || strlen <= 0) return res;

        TrieNode *root = new TrieNode;
        memset(root, 0, sizeof(TrieNode));
        build_TrieNode(s, root);

        for ( i = 0; i < len; i++)
        {
            if (comparestr(root, p[i]))
                res.push_back(true);
            else res.push_back(false);
        }

        delete root;
        return res;
    }
};

int main(void)
{
    {
        string str[]{"ello","world","test","hle","aaaa","ld"};
        vector<string> strtemp(str, str + sizeof(str) / sizeof(string));
        Substr test;
        auto var = test.chkSubStr(strtemp, strtemp.size(), "helloworld");
        for each (auto vart in var)
        {
            cout << boolalpha << vart << endl;
        }
    }

    cin.get();
    return 0;
}