suggested problem Stanford, first problem

BalancedPar.cpp

//https://web.stanford.edu/class/cs9/lectures/RecursionProbSetA.pdf
#include <iostream>
#include <vector>

using namespace std;

class Solution {
    public:
        enum TypeParenthesis {Open = 1, Close = -1};
        
        void generateParentheses(int size) {
            if(size % 2 != 0) {
                return;
            }
            vector <char> result;
            this -> generateParentheses(TypeParenthesis::Open, result, size);
            this -> generateParentheses(TypeParenthesis::Close, result, size);
        }
    private:
        void generateParentheses(TypeParenthesis type, vector <char> &result, int size, int balance = 0) {
            if(balance == 0 and result.size() == size) {
                if(type == TypeParenthesis::Close) {
                    /**=== Instead of printing it could be added to a vector result === **/
                    for(auto c: result) {
                        std::cout << c;
                    }
                    /**===**/cout << endl;/**===**/
                }
                return;
            }
            else if(result.size() == size) {
                return;
            }
            if(balance < 0)
                return;
            if(type == TypeParenthesis::Open)
                result.push_back('(');
            else
                result.push_back(')');
            generateParentheses(TypeParenthesis::Open, result, size, balance + type);
            generateParentheses(TypeParenthesis::Close, result, size, balance + type);
            result.pop_back();
        }

};
int main() {

    Solution sol;
    sol.generateParentheses(12);

    return 0;
}