5.4

setlocale(0, ".1251");

    const int n = 5;
    int arr[n][n];
    for (int i = 0; i<n; i++) {
        for (int j = 0; j<n; j++) {
            arr[i][j] = rand() % 10;
            cout << arr[i][j] << " ";
        }
        cout << "\n";
    }
    cout << "Вектор главной диагонали : ";
    for (int i = 0; i<n; i++)
        for (int j = 0; j<n; j++)
            if (i == j)
                cout << arr[i][j] << " ";
    cout << endl;
        system("pause");
    return 0;