13291 . 单选题 Puls

如下 C++ 代码执⾏后,输⼊ 4 后,输出的数字图形是?

int n; 
cin >> n; 
for (int i = n; i > 0; i--) {
    for (int j = 0; j < n - i; j++)
        cout << "0 ";
    for (int k = 0; k < i; k++) 
        cout << k + 1 << " ";
    cout << endl;
}