#include <iostream>
using namespace std;

int main()
{
    int *A,n,x, ch;
    int i,j;
    
    cout << "Enter dimension : " ;
    cin >> n;
    
    A = new int[n];
    
    do
    {
        cout << "\n\n---Diagonal matrix---" << endl;
        cout << "1. Create " << endl;
        cout << "2. Get " << endl;
        cout << "3. Set " << endl;
        cout << "4. Display " << endl;
        cout << "5. Exit " << endl;
        cout << "Enter your choice : ";
        cin >> ch;
        
        switch(ch)
        {
            case 1 :
            cout << "Enter the diagonal elements : \n";
            for (int i=1; i<=n; i++)
                cin >> A[i-1];
            break;
            
            case 2 :
            cout << "Enter indices : ";
            cin >> i >> j;
            if (i==j)
                cout << "Element is : " << A[i-1] << endl;
            else 
                cout << "Element is : 0 " << endl;
            break;
            
            case 3 : 
            cout << "Enter the element : ";
            cin >> x;
            cout << "Enter the indices : ";
            cin >> i >> j;
            if (i==j)
            {
                A[i-1] = x;
                cout << "Element is inserted "<< endl;
            }
            else 
            cout << "Element cannot be inserted at those indices!" << endl;
            break;
            
            case 4 :
            for (int i=1; i<=n; i++)
            {
                for(int j=1; j<=n; j++)
                {
                    if (i==j)
                        cout << A[i-1] << " ";
                    else
                        cout << "0 ";
                }
                cout << endl;
            }
            break;
            
        }
        
    }
    while(ch != 5);
    
    return 0;
}