Răspuns:
#include<iostream>
using namespace std;
int n,i,j,a[20][20],ok=1,p;
int main()
{
cin>>n;
for(i=1;i<=n;i++)
for(j=1;j<=n;j++)
cin>>a[i][j];
for(j=n;j>=1 && ok;j--)
for(i=1;i<=n && ok;i++)
if(a[i][j]%3==0)ok=0,p=j;
if(!ok)
for(i=1;i<=n;i++)
cout<<a[i][p]<<" ";
else cout<<"nu exista";
}
Explicație: