Hello, I'm having trouble finding the correct Second best MST The procedures i follow are :

Finding MST by kruskal

Iterate over all edges of the found MST and refrain from taking each edge individually

Rerunning Kruskal to find MST

trace the minimum found MST

Here is my code

    #define push_back pb
    #define make_pair mp
    vector < pair < int, int >> taken; //Used to store edges taken in MST

    for (int i = 0; i < e; i++) { //Finding initial MST
        pair < int, ii > front = EdgeList[i];
        if (!isSameSet(front.second.first, front.second.second)) {
            mst_cost += front.first;
            taken.pb(mp(front.second.first, front.second.second)); //Adding taken edge 
            unionSet(front.second.first, front.second.second);
        }

    }

    int secondMST = INF;

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

        initSet(n + 1);
        int tempst = 0;

        for (int j = 0; j < e; j++) {
            pair < int, ii > front = EdgeList[j];
            if ((front.second.first == taken[i].first) && (front.second.second == taken[i].second))
                continue;

            else if (!isSameSet(front.second.first, front.second.second)) {
                tempst += front.first;
                unionSet(front.second.first, front.second.second);
            }
        }
        secondMST = min(secondMST, tempst);
    }

    cout << mst_cost << " " << secondMST << endl;