#include <iostream>
using namespace std;

class Diagonal 
{
    private :
        int n; 
        int *A;
 
    public :
    
        Diagonal(int n)
        {
            this->n = n;
            A = new int[n];
        }
 
        void set (int i, int j , int x);
        int get (int i, int j);
        void display();
        ~Diagonal()
        {
            delete []A;
        }
};
 
void Diagonal :: set(int i, int j, int x)
{
    if(i==j)
        A[i-1] = x;
}
 
int Diagonal :: get(int i ,int j)
{
    if (i==j)
        return A[i-1];
    else 
        return 0;
}
 
void Diagonal :: display()
{
    for (int i=0; i<n; i++)
    {
        for (int j=0; j<n; j++)
        {
            if (i==j)
                cout << A[i] << " ";
            else
                cout << "0 ";
        }
        cout << endl;
    }
}

int main() {
    
    Diagonal m(4) ;
    
    m.set(1,1,1);
    m.set(2,2,2);
    m.set(3,3,3);
    m.set(4,4,4);
    
    m.display();

    return 0;
}