C++：用输入字符构造 4*4 空心正方形的代码实现

```cpp #include <iostream> using namespace std; int main() { char ch; cin >> ch; for (int i = 0; i < 4; i++) { for (int j = 0; j < 4; j++) { if (i == 0 || i == 3 || j == 0 || j == 3) { cout << ch; } else { cout << " "; } } cout << endl; } return 0; } ``` ######[AI问答 | 116点数解答 | 2025-12-06 14:49:27]