Codeforces Round #781 (Div. 2)

Problem Link:  https://codeforces.com/contest/1665/problem/C

 Solution in C++:

///La ilaha illellahu muhammadur rasulullah

///******Bismillahir-Rahmanir-Rahim******///

///Abul Hasnat  Tonmoy

///Department of CSE,23rd batch

///Islamic University,Bangladesh

///**********ALLAH IS ALMIGHTY************///

#include <bits/stdc++.h>

using namespace std;

int main()

{

    long long a, n,t,i,j,c,ans,v,x;

    cin>>t;

    while(t--)

    {

        map<long long,long long>mp;

        vector<long long>v;

        priority_queue<long long>pq;

        v.push_back(1);

        c=0,ans=0;

        cin>>n;

        for(i=0; i<n-1; i++)

        {

            cin>>a;

            mp[a]++;

        }

        for(auto j:mp)

        {

            v.push_back(j.second);

        }

        sort(v.begin(),v.end());

        ans=v.size();

        for(i=0; i<v.size(); i++)

        {

            int  m=v[i];

            m-=i+1;

            if(m>0)

                pq.push(m);

        }

        while(!pq.empty())

        {

            int m=pq.top();

            pq.pop();

            if(m<=c)break;

            m--;

            c++;

            ans++;

               pq.push(m);

        }

        cout<<ans<<endl;

    }

}