题解

#include<iostream>
using namespace std;
int a[110],vis[110],n;
void dfs(int p){
if(p==n+1){
for(int i=1;i<=n;++i){
cout<<a[i]<<" ";
}
cout<<endl;
return ;
}
for(int i=1;i<=n;++i){
if(vis[i]==0){
vis[i]=1;
a[p]=i;
dfs(p+1);
vis[i]=0;
}
}
}
int main(){
cin>>n;
dfs(1);
return 0;
}