Unire

#include <bits/stdc++.h>
#define N 1000001
using namespace std;
vector <int> nod[N];
deque <int> coada;
int n,viz[N],nrc;
ifstream f("unire.in");
ofstream g("unire.out");

int BFS(int Nod)
{
    int x,NodMin=n+1;
    coada.push_back(Nod);
    if(Nod<NodMin)
        NodMin=Nod;
    viz[Nod]=nrc;
    while(!coada.empty())
    {
        x=coada.front();
        coada.pop_front();
        for(unsigned int i=0;i<nod[x].size();++i)
            if(!viz[nod[x][i]])
            {
                if(nod[x][i]<NodMin)
                    NodMin=nod[x][i];
                coada.push_back(nod[x][i]),viz[nod[x][i]]=nrc;
            }
    }
    return NodMin;
}

int main()
{
    int m,c;
    f>>n>>m>>c;
    int x,y;
    while(m--)
        f>>x>>y,nod[x].push_back(y),nod[y].push_back(x);
    int NodMin;
    unsigned long long int sol=0;
    for(int i=1;i<=n;++i)
        if(!viz[i])
        {
            ++nrc,NodMin=BFS(i);
            if(NodMin!=1)
                sol+=NodMin+1;
        }
    if(c==1)
        g<<--nrc;
    else
        g<<sol;
    return 0;
}