Language: C++

#include<bits/stdc++.h>
using namespace std;
#define ULL unsigned long long
ULL n,m;
ULL a,b;
ULL sum1,sum2;
ULL num[100];
bool cmd(ULL x,ULL y)
{
    return x>y;
}
map<ULL,ULL>q;
ULL C(ULL n,ULL m)
{
    if(n<m) return 0;
    ULL ans=1;
    for(int i=0;i<m;i++) ans=ans*(ULL)(n-i)/(ULL)(i+1);
    return ans;
}
int main()
{
    cin>>n>>a>>b;
    for(int i=1;i<=n;i++)
    {
        cin>>num[i];
        q[num[i]]++;
    }
    sort(num+1,num+1+n,cmd);
    for(int i=1;i<=a;i++)
    {
        sum1+=num[i];
    }
    for(int i=1;i<=b;i++)
    {
        sum2+=num[i];
    }
    printf("%.10f\n",max(((double)sum1*1.0/a*1.0,(double)sum2*1.0/b*1.0));
    if(sum1*1.0/a*1.0>=sum2*1.0/b*1.0)
    {
         ULL ans=1;
         for(map<ULL,ULL>::reverse_iterator it=q.rbegin();it!=q.rend();it++)
         {
             ULL x=it->second;
             if(a>=x)
             {
                 a-=x;
             }
             else
             {
                 ans*=C(x,a);
                 break;
             }
         }
         cout<<ans<<endl;
    }
    else
    {
         ULL ans=1;
         for(map<ULL,ULL>::reverse_iterator it=q.rbegin();it!=q.rend();it++)
         {
             ULL x=it->second;
             if(b>=x)
             {
                 b-=x;
             }
             else
             {
                 ans*=C(x,b);
                 break;
             }
         }
         cout<<ans<<endl;
    }
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:37:25: error: no matching function for call to 'max(double)'
   37 |     printf("%.10f\n",max(((double)sum1*1.0/a*1.0,(double)sum2*1.0/b*1.0));
      |                      ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   candidate expects 2 arguments, 1 provided
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 1 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   template argument deduction/substitution failed:
a.cc:37:25: note:   mismatched types 'std::initializer_list<_Tp>' and 'double'
   37 |     printf("%.10f\n",max(((double)sum1*1.0/a*1.0,(double)sum2*1.0/b*1.0));
      |                      ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   candidate expects 2 arguments, 1 provided