Метро не в Екатеринбурге

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <map>
#include <queue>
#include <set>

using namespace std;
struct top
{
    int num;
    bool was;
    vector <top*> next;
};

top* newtop(int num)
{
    top* prom = new top();
    prom->num = num;
    prom->was = false;
    return prom;
}

void findbreas(top* Top)
{
    queue <top*>nexta;

    nexta.push(Top);

    while (nexta.size() != 0)
    {
        top* prom = nexta.front();
        nexta.pop();
        for (auto i = prom->next.begin(); i != prom->next.end(); i++)
        {
            if ((*i)->was != true)
            {
                nexta.push(*i);
                (*i)->was = true;
            }
        }
    }
}
int main()
{
    int n, k, m;
    int prom, promk;
    cin >> n >> k >> m;

    map<int, vector<int>> stans;
    map<int, top*>graf;

    for (int i = 1; i <= n; i++)
    {
        top* New = newtop(i);
        graf[New->num] = New;
    }

    for (int i = 1; i <= k; i++)
    {
        cin >> prom >> promk;
        graf[prom]->next.push_back(graf[promk]);
        graf[promk]->next.push_back(graf[prom]);
    }

    int svaz = 0;
    for (auto i = graf.begin(); i != graf.end(); i++)
    {
        if (i->second->was != true)
        {
            findbreas(i->second);
            svaz++;
        }
    }
    cout << svaz - 1<< endl;

    system("pause");
    return 0;
}