quayluiHoanVi

#include<iostream>
using namespace std;

int a[100], n, dd[100] = {0};

void write(){
    for(int i=1; i <= n; i++){
        cout<<a[i];
    }
    cout<<endl;
}

void backTrack(int k){
    if(k > n){
        write();
        return ;
    }
    for(int i = 1; i <= n; i++){
        if(dd[i] == 0){
            a[k] = i;
            dd[i] = 1;
            backTrack(k + 1);
            dd[i] = 0;
        }
    }
}

main(){
    cin>>n;
    backTrack(1);
}