Hi, My below code return a output and not passing the testcase even it satisfy the condition. Can somebody help me why it is failing? Problem link : https://cses.fi/problemset/task/2205/ For input : 3

My output: 000 100 110 010 101 001 011 111 CSES OUTPUT: 000 001 011 010 110 111 101 100 Code:

#include <bits/stdc++.h>
#define ll long long int
#define f(i, p, q) for (int i = p; i < q; i++)
using namespace std;
vector<string>v;
void solve(int n,string s){
    if(s.length()>=n){
        v.push_back(s);
        return;
    }
    solve(n,s+'0');
    solve(n,s+'1');
}
int countOne(string s){
    int count=0;
    for(int i=0;i<s.length();i++){
        if(s[i]=='1')count++;
    }
    return count;
}
int main()
{
   
    int n;
    cin>>n;

    solve(n,"");
    map<int,vector<string>>mp;
    int ans=0;
    for(int i=0;i<v.size();i++){
        mp[countOne(v[i])].push_back(v[i]);
    }
    int l=0;
    bool x= false;
    for(ll i=0;i<=pow(2,n);i++){
        if(mp[l-1].size()>0 && x){
            string g =mp[l-1][mp[l-1].size()-1];
            cout<<g<<"\n";
            mp[l-1].pop_back();
            x=false;
        }else if(mp[l].size()>0 && !x){
            string g =mp[l][mp[l].size()-1];
            cout<<g<<"\n";
            mp[l].pop_back();
            x=true;      
        }
        if(mp[l-1].size()==0){   
           l++;
           x= true;
        }
    }  
}