Generator grafuri neorientate cu nr specificat de componente conexe

/// generator graf neorientat cu n componente conexe
#include <iostream>
#include <vector>
#include <stdlib.h>     /* srand, rand */
#include <time.h>       /* time */
#include <fstream>

using namespace std;

int muchii[600002];
int nr_muchii = 0;

ofstream fout("graf.txt");

struct nod {
    int cc;             /// din ce componenta conexa face parte
    vector<int> vecini; /// indicii nodurilor vecine
};

nod noduri[200001];
int fr[200001];

void adaugaVecin(int a, int b){
    noduri[a].vecini.push_back(b);
}

void refaDFS(int a, int newValForCC){
    if (noduri[a].cc==newValForCC) return; /// deja l-am vizitat si probabil ca sunt intr-o bucla
    noduri[a].cc = newValForCC;
    for(int i=0; i<noduri[a].vecini.size(); i++)
        refaDFS(noduri[a].vecini[i], newValForCC);
}

int vecini(int x, int y){
    for(int i=0; i<noduri[x].vecini.size(); i++)
        if (y==noduri[x].vecini[i]) return 1;
    return 0;
}

int main()
{
    int n,m,cx;
    int bn, bm, bcx;
    cout << "Introduceti numarul de noduri: ";
    cin >> n;
    cout << "Introduceti numarul de muchii:";
    cin >> m;
    cout << "Introduceti numarul de componente conexe:";
    cin >> cx;
    bn=n,bm=m,bcx=cx;
    srand (time(NULL));


    int muchii_in_plus=0;

    for(int i=1; i<=n; i++)
        noduri[i].cc=i;

    int conexe = n;
    while (conexe>cx)
    {
        int x = rand() % n + 1;
        int y = rand() % n + 1;
        if (noduri[x].cc!=noduri[y].cc)
        {
            adaugaVecin(x,y);
            adaugaVecin(y,x);
            if (noduri[x].cc < noduri[y].cc) refaDFS(noduri[y].cc, noduri[x].cc);
            if (noduri[x].cc > noduri[y].cc) refaDFS(noduri[x].cc, noduri[y].cc);
            conexe--;
            m--;

            muchii[nr_muchii] = x;
            muchii[nr_muchii+1] = y;
            nr_muchii+=2;
        }
    }
    while(m)
    {
        int x = rand() % n + 1;
        int y = rand() % n + 1;
        if (x==y) continue;
        if (noduri[x].cc==noduri[y].cc){
            m--;
            muchii[nr_muchii] = x;
            muchii[nr_muchii+1] = y;
            nr_muchii+=2;
        }
    }

    fout << n << ' ' << bm << '\n';
    for(int i=0; i<nr_muchii; i+=2)
    {
        if (muchii[i]<muchii[i+1]) fout << muchii[i] << ' ' << muchii[i+1] << '\n';
        else fout << muchii[i+1] << ' ' << muchii[i] << '\n';
    }

    return 0;
}