Problema 1/ 02 martie

#include<iostream>
using namespace std;
int a[21][21],sw;
int b[21][21],n;
 void royfoyd()
{ for(int k=1;k<=n;k++)
      for(int i=1;i<=n;i++)
          for(int j=1;j<=n;j++)
              if(b[i][j]&&b[k][j])
                 b[i][j]=1;
}
int circuit()
{
     for(int i=1;i<=n;i++)
        if(b[i][i])
            return 1;
     return 0;
}
int turneu()
{
      for(int i=1;i<=n;i++)
         for(int j=1;j<=n;j++)
            if(i!=j && a[i][j] +a[i][j]==0)
              return 0;
      return 1;
}
int main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
        {
            cin>>a[i][j];
            b[i][j]=a[i][j];
        }
    royfloyd();

    cout<<"a) ";
    if(circuit()) cout<<"graful are circuite\n";
    else cout<<"graful nu are circuite\n";

    cout<<"b) nu exista drum intre:\n";
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
            if(i!=j && !b[i][j])
                cout<<i<<' '<<j<<'\n';

    cout<<"c) ";
    if(turneu()) cout<<"graful este turneu\n";
    else cout<<"graful nu este turneu\n";

    cout<<"d) ";
    if(complet()) cout<<"graful este complet\n";
    else cout<<"graful nu este complet\n";
    return 0;
}