Generate all the combinations of well formed parentheses || in cpp solution

 

#include <iostream>

#include <algorithm>

#include <vector>

using namespace std;

void solve(vector<string> &ans, int open, int close, string s, int n)

{

    if (s.size() == 2 * n)

    {

        ans.push_back(s);

        return;

    }

    if (open < n)

    {

        solve(ans, open + 1, close, s + '(', n);

    }

    if (close < open)

    {

        solve(ans, open, close + 1, s + ')', n);

    }

}

vector<string> generete(int n)

{

    vector<string> ans;

    solve(ans, 0, 0, "", n);

    return ans;

}

int main()

{

    int n ;

cin>>n;

    vector<string> ans = generete(n);

    sort(ans.begin(), ans.end());

    cout << "{ ";

    for (int i = 0; i < ans.size(); i++)

    {

        cout << ans[i] << ", ";

    }

    cout << "}";

}