题解

#include<bits/stdc++.h>
using namespace std;
const int MAXN = 730;
char g[MAXN][MAXN];
void draw(int x, int y, int n) {
    if (n == 1) {
        g[x][y] = 'X';
        return;
    }
    int s = 1;
    for(int i = 1; i <= n-1; ++i) s *= 3;
    int ns = s / 3; 
    draw(x, y, n-1);
    draw(x, y + 2*ns, n-1);
    draw(x + ns, y + ns, n-1);
    draw(x + 2*ns, y, n-1);
    draw(x + 2*ns, y + 2*ns, n-1);
}
int main() {
    int T;
    cin >> T;
    while(T--) {
        int n;
        cin >> n;
        int s = 1;
        for(int i = 1; i <= n-1; ++i) s *=3;
        memset(g, '  ', sizeof(g));
        draw(0,0,n);
        for(int i = 0; i < s; ++i) {
            for(int j = 0; j < s; ++j) {
                cout << g[i][j];
            }
            cout << endl;
        }
        cout << "-" << endl;
    }
    return 0;
}