WordBreak using Trie

class Solution
{
public:
    typedef struct TrieNode {
        map<char, pair<int, TrieNode*>> children; 
        bool isEndOfWord = false;
    } TrieNode;
    void insert(TrieNode *root, string str) {
        TrieNode *curr = root;
        for(int i = 0; i < str.length(); i++) {
            if(curr -> children[str[i]].second == nullptr) {
                curr -> children[str[i]].second = new TrieNode();
            }
            curr -> children[str[i]].first++;
            curr = curr -> children[str[i]].second; 
        }
        curr -> isEndOfWord = true;
    }
    bool query(TrieNode *root, string str) {
        TrieNode *curr = root;
        for(int i = 0; i < str.length(); i++) {
            if(curr -> children[str[i]].second == nullptr) 
            return false;
            curr = curr -> children[str[i]].second; 
        }
        if(curr != nullptr && curr -> isEndOfWord) return true;
    }
    int solve(string str, TrieNode *root) {
        if(str.length() == 0) return 1;
        for(int i = 1; i <= str.length(); i++) {
            if(query(root, str.substr(0, i)) && solve(str.substr(i), root))
            return 1;
        }
        return 0;
    }
    int wordBreak(string A, vector<string> &B) {
        //code here
        TrieNode *root = new TrieNode();
        for(int i = 0; i < B.size(); i++) {
            insert(root, B[i]);
        }
        return solve(A, root);
    }
};