func_code_string: #include <bits/stdc++.h>   using namespace std;   #define mod 1000000007   #define int long long   #define double long double   #define pb push_back   #define mp make_pair   #define endl   n    #define all(x) x.begin(),x.end()   #define fill(a,b) memset(a,b,sizeof(a))   #define sz(x) (int)x.size()   #define ff first   #define ss second   #define lb lower_bound   #define ub upper_bound   #define bs binary_search   #define rep(i, begin, end) for (__typeof(end) i = (begin) - ((begin) > (end)); i != (end) - ((begin) > (end)); i += 1 - 2 * ((begin) > (end)))   #define deb(x) cout<<#x<<   <<x<<endl;   #define T int t; cin>>t; while(t--)   #define fst ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);      int firstMissingPositive(int arr[], int n)   {               for (int i = 0; i < n; i++) {              while (arr[i] >= 1 && arr[i] <= n                  && arr[i] != arr[arr[i] - 1]) {               swap(arr[i], arr[arr[i] - 1]);           }       }          for (int i = 0; i < n; i++) {           if (arr[i] != i + 1) {               return i + 1;           }       }             return n + 1;   }      signed main()   {          fst;      #ifndef ONLINE_JUDGE       freopen( input3.txt ,  r , stdin);       freopen( output3.txt ,  w , stdout);   #endif                 T{           int n,p,q, m,h, k, sum = 0, cnt=0, x, y, z, flag = 0, pos, diff,r=0,l=0,u=0,d=0,cnt1=0,cnt0=0,cnt2=0,ans,mi=INT_MAX,mx=INT_MIN;           cin>>n;                      int a[n];           vector<int> v,v1,v2;           set<int> st;           map<int,int> mp;              rep(i,0,n) {               cin>>x;               if(find(all(st),x) != st.end())                 v.pb(x);               st.insert(x);           }              for(auto i:st) cout<<i<<   ;           sort(all(v));              for(auto i:v) cout<<i<<   ;                 cout<<endl;              v.clear();           st.clear();          }   }   