nr muchii, noduri izolate, noduri pare, graf complet sau nu

#include <iostream>
#include <fstream>
using namespace std;

int n,m,a[101][101];
ifstream f("fmmviata.in");

void citire()
{
    int i,j;
    f>>n;
    while (f>>i>>j) {a[i][j]=a[j][i]=1;
                     m++;}
}

int gr(int nod)
{
    int x,s=0;
    for(x=1;x<=n;x++)
        s=s+a[nod][x];
    return s;

}

int main()
{
    citire();
    int i,j,p=0,ok=0;
    cout<<"nr muchii: "<<m;
    cout<<endl<<"grade izolate: ";
    for(i=1;i<=n;i++)
        if(gr(i)==0)p++;
    cout<<p;
    cout<<endl<<"noduri grad par: ";
    for(i=1;i<=n;i++)
        if(gr(i)%2==0) cout<<i<<" ";
    for(i=1;i<=n;i++)
        if(gr(i)!=n-1)ok=1;
    if(ok==0)cout<<endl<<"graful este complet.";
    else cout<<endl<<"graful nu este complet.";
}