QwQ：

#include <bits/stdc++.h>
using namespace std;
long long a[100];
long long b[100];
long long n,r;
bool f[100];
void print () {
	cout<<"     "<<a[b[1]]<<"     ";
	for (int i=2;i<=r;i++) 
	  cout<<a[b[i]]<<(i<r ? "     " : "");
}
void dfs (int deep) {
	if (deep>r) {
		print ();
		cout<<"\n";
		return ;
	}
	for (int i=1;i<=n;i++) {
		if (f[i]==false && ! (deep==1 && a[i]==0)) {
			f[i]=true;
			b[deep]=i;
			dfs (deep+1);
			f[i]=false;
		}
	}
}
int main() {
	cin>>n;
	r=n;
	for (int i=1;i<=n;i++) a[i]=i;
	dfs (1);
	return 0;
}