题解

#include <iostream>
#include <cstdio>
using namespace std;
int main() { 
    int t; scanf("%d", &t);
	for (int i=1; i<=t; i++) {
		int n; scanf("%d", &n);
		int c = n;
		int *a = new int[n+1]();
		Loop:
        if (c <= 3) goto END;
		for (int j = 1, cnt = 0; j <= n; j++) {
			if (a[j] == 0) {
				cnt ++ ;
				if (cnt == 2) {
					cnt = 0;
					a[j] = 1;
					c--;
				}
			}
		}
		if (c<=3) goto END;
		for (int j = 1, cnt = 0; j <= n; j++) {
			if (a[j] == 0) {
				cnt ++ ;
				if (cnt == 3) {
					cnt = 0;
					a[j] = 1;
					c--;
				}
			}
		}
		if (c>3) goto Loop;
		END:
        bool first = true;
		for (int j=1; j<=n; j++) {
			if (!a[j] && first) { printf("%d", j); first = !first; }
            else if (!a[j]) printf(" %d", j);
 		}
 		putchar('\n');
        delete []a;
	}         
	return 0;
}