C++ :

#include<iostream>
using namespace std;
int main()
{
	int n,a,b;
	cin>>n;
	for (int k=1; k<=n; k++)
	{
		cin>>a>>b;
		if (a==1)	//a==1
			for (int i=1; i<=b; i++) cout<<"X"<<endl;
		else
		{
			cout<<"X";
			for (int i=2; i<=a-1; i++) cout<<" ";
			cout<<"X"<<endl;	//X的第一行
			for (int t=1; t<=b; t++)	//重复b次
			{
				for (int i=2; i<=a/2; i++)	//上半部分
				{
					for (int j=1; j<=a; j++)
						if (i==j || i+j==a+1) cout<<"X";
						else if (i+j<=a) cout<<" ";
					cout<<endl;
				}
				for (int i=a/2+1; i<=a; i++)//下半部分
				{
					for (int j=1; j<=a; j++)//输出前面
						if (i==j || i+j==a+1) cout<<"X";
						else if (i>j) cout<<" ";
					cout<<endl;
				}
			}
		}
		if (k<n) cout<<endl;
	}
	return 0;
}