tare conex

#include <iostream.h>
#include <fstream.h>
int a[20][20];
int main (){
    int i,j,k,n,x,y;
    ifstream f("in.txt");
    f>>n;
    for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
            f>>a[i][j];
    for(k=1;k<=n;k++)
        for(i=1;i<=n;i++)
            for(j=1;j<=n;j++)
                if(!a[i][j] && a[i][k] && a[k][j] && i!=k && j!=k)
                    a[i][j]=1;
    for(i=1;i<=n;i++){
        for(j=1;j<=n;j++)
            cout<<a[i][j]<<" ";
        cout<<endl;
    }
    k=1;
    for(i=1;i<=n && k;i++){
        for(j=1;j<=n && k;j++)
            if(i!=j && a[i][j]!=1)
                k=0;
    }
    if(k)
        cout<<"este tare tare foarte tare conex";
    else
        cout<<"nu este tare tare foarte tare conex";
}