运用数学规律解题

参考代码:

```c++

#include<iostream>

using namespace std;

int main() {

int i, j;

int a, b, n;

cin >> n;

while (n--) {

cin >> a >> b;

while (b--) {

for (i = 0; i < a - 1; i++) {

for (j = 0; j < a; j++) {

if (i == j || i + j == a - 1) {

cout << "X";

}

else {

cout << " ";

}

}

cout << endl;

}

}

cout << "X";

for (int h = 0; h < a - 2; h++) {

cout << " ";

}

cout << "X";

cout << endl << endl;

}

return 0;

}

```