参考答案：

#include<iostream>
#include<math.h>

using namespace std;

int main()
{
    int a, ar[55];
    int i, j, k;
    cin >> a;
    for (i = 0; i < a; ++i)
    {
        while (cin >> ar[i])
        {
            for (j = 1; j <= ar[i]; ++j)
            {
                for (k = 1; k <= ar[i]; ++k)
                    if (abs(j - (ar[i] + 1) / 2) + abs(k - (ar[i] + 1) / 2) < (ar[i] + 1) / 2)cout << '*';
                    else cout << ' ';
                cout << endl;
            }
            break;
        }
    }

    return 0;
}