Language: C++

#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ld=long double;
using ull=unsigned long long;
using uint=unsigned int;
using pcc=pair<char,char>;
using pii=pair<int,int>;
using pll=pair<ll,ll>;
using pdd=pair<double,double>;
using tuplis=pair<ll,pll>;
using tuplis2=pair<pll,ll>;
template<class T> using pq=priority_queue<T,vector<T>,greater<T>>;
const ll LINF=0x1fffffffffffffff;
const ll MOD=1000000007;
const ll MODD=998244353;
const int INF=0x3fffffff;
const ld DINF=numeric_limits<ld>::infinity();
const ld EPS=1e-8;
const vector<pii> four={{-1,0},{0,1},{1,0},{0,-1}};
#define _overload4(_1,_2,_3,_4,name,...) name
#define _overload3(_1,_2,_3,name,...) name
#define _rep1(n) for(ll i=0;i<n;++i)
#define _rep2(i,n) for(ll i=0;i<n;++i)
#define _rep3(i,a,b) for(ll i=a;i<b;++i)
#define _rep4(i,a,b,c) for(ll i=a;i<b;i+=c)
#define rep(...) _overload4(__VA_ARGS__,_rep4,_rep3,_rep2,_rep1)(__VA_ARGS__)
#define _rrep1(n) for(ll i=n-1;i>=0;i--)
#define _rrep2(i,n) for(ll i=n-1;i>=0;i--)
#define _rrep3(i,a,b) for(ll i=b-1;i>=a;i--)
#define _rrep4(i,a,b,c) for(ll i=a+(b-a-1)/c*c;i>=a;i-=c)
#define rrep(...) _overload4(__VA_ARGS__,_rrep4,_rrep3,_rrep2,_rrep1)(__VA_ARGS__)
#define each(i,a) for(auto &i:a)
#define sum(...) accumulate(range(__VA_ARGS__),0LL)
#define dsum(...) accumulate(range(__VA_ARGS__),double(0))
#define _range(i) (i).begin(),(i).end()
#define _range2(i,k) (i).begin(),(i).begin()+k
#define _range3(i,a,b) (i).begin()+a,(i).begin()+b
#define range(...) _overload3(__VA_ARGS__,_range3,_range2,_range)(__VA_ARGS__)
#define _rrange(i) (i).rbegin(),(i).rend()
#define _rrange2(i,k) (i).rbegin(),(i).rbegin()+k
#define _rrange3(i,a,b) (i).rbegin()+a,(i).rbegin()+b
#define rrange(...) _overload3(__VA_ARGS__,_rrange3,_rrange2,_rrange)(__VA_ARGS__)
#define elif else if
#define unless(a) if(!(a))
#define mp make_pair
#define mt make_tuple
#define INT(...) int __VA_ARGS__;in(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;in(__VA_ARGS__)
#define STR(...) string __VA_ARGS__;in(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__;in(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__;in(__VA_ARGS__)
#define vec(type,name,...) vector<type> name(__VA_ARGS__)
#define VEC(type,name,size) vector<type> name(size);in(name)
#define vv(type,name,h,...) vector<vector<type>>name(h,vector<type>(__VA_ARGS__))
#define VV(type,name,h,...) vector<vector<type>>name(h,vector<type>(__VA_ARGS__));in(name)
#define vvv(type,name,h,w,...) vector<vector<vector<type>>>name(h,vector<vector<type>>(w,vector<type>(__VA_ARGS__)))
volatile struct SETTINGS{SETTINGS(){cout<<fixed<<setprecision(20);};};volatile SETTINGS _SETTINGS();
inline constexpr ll gcd(ll a,ll b){if(!a||!b)return 0;while(b){ll c=b;b=a%b;a=c;}return a;}
inline constexpr ll lcm(ll a,ll b){if(!a||!b)return 0;return a*b/gcd(a,b);}
template<class T> inline constexpr T min(vector<T> &v){return *min_element(range(v));}
inline char min(string &v){return *min_element(range(v));}
template<class T> inline constexpr T max(vector<T> &v){return *max_element(range(v));}
inline char max(string &v){return *max_element(range(v));}
inline constexpr ll intpow(const ll&a,const ll&b){if(b==0)return 1;ll ans=intpow(a,b/2);return ans*ans*(b&1?a:1);}
inline constexpr ll modpow(const ll&a,const ll&b,const ll&mod=MOD){if(b==0)return 1;ll ans=modpow(a,b/2,mod);ans=ans*ans%mod;if(b&1)ans=ans*a%mod;return ans;}
template<typename T>
inline constexpr bool update_min(T &mn,const T &cnt){if(mn>cnt){mn=cnt;return 1;}else return 0;}
template<typename T>
inline constexpr bool update_max(T &mx,const T &cnt){if(mx<cnt){mx=cnt;return 1;}else return 0;}
inline int scan(){return getchar();}
inline void scan(bool &a){int b;scanf("%d",&b);a=b;}
inline void scan(int &a){scanf("%d",&a);}
inline void scan(unsigned &a){scanf("%u",&a);}
inline void scan(ll &a){scanf("%lld",&a);}
inline void scan(ull &a){scanf("%llu",&a);}
inline void scan(char &a){scanf("%c",&a);}
inline void scan(float &a){scanf("%f",&a);}
inline void scan(double &a){scanf("%lf",&a);}
inline void scan(ld &a){scanf("%Lf",&a);}
template<class T> inline istream &operator >> (istream &is, vector<T> &vec);
template<class T,size_t size> inline istream &operator >> (istream &is, array<T,size> &vec);
template<class T,class L> inline istream &operator >> (istream &is, pair<T,L> &p);
template<class T> inline istream &operator >> (istream &is, T vec[]);
template<class T> inline istream &operator >> (istream &is, vector<T> &vec){each(i,vec)scan(i);return is;}
template<class T,size_t size> inline istream &operator >> (istream &is, array<T,size> &vec){each(i,vec)scan(i);return is;}
template<class T,class L> inline istream &operator >> (istream &is, pair<T,L> &p){scan(p.first);scan(p.second);return is;}
template<class T> inline istream &operator >> (istream &is, T vec[]){each(i,vec)scan(i);return is;}
template<class T> inline void scan(T &a){cin>>a;}
inline void in(){}
template <class Head, class... Tail>
inline void in(Head &&head,Tail&&... tail){scan(head);in(move(tail)...);}
inline void print(){printf("\n");}
inline void print(const bool &a){printf("%d",a);}
inline void print(const int &a){printf("%d",a);}
inline void print(const unsigned &a){printf("%u",a);}
inline void print(const ll &a){printf("%lld",a);}
inline void print(const ull &a){printf("%llu",a);}
inline void print(const char &a){printf("%c",a);}
inline void print(const char a[]){printf("%s",a);}
inline void print(const float &a){printf("%f",a);}
inline void print(const double &a){printf("%lf",a);}
inline void print(const ld &a){printf("%Lf",a);}
inline void print(const bool &&a){printf("%d",a);}
inline void print(const int &&a){printf("%d",a);}
inline void print(const unsigned &&a){printf("%u",a);}
inline void print(const ll &&a){printf("%lld",a);}
inline void print(const ull &&a){printf("%llu",a);}
inline void print(const char &&a){printf("%c",a);}
inline void print(const float &&a){printf("%f",a);}
inline void print(const double &&a){printf("%lf",a);}
inline void print(const ld &&a){printf("%Lf",a);}
template<class T> inline ostream &operator << (ostream &os,const vector<T> &vec);
template<class T,size_t size> inline ostream &operator << (ostream &os,const array<T,size> &vec);
template<class T,class L> inline ostream &operator << (ostream &os,const pair<T,L> &p);
template<class T> inline typename enable_if<is_same<T,const char>::value==0,ostream>::type &operator << (ostream &os,T vec[]);
template<class T> inline ostream &operator << (ostream &os,const vector<T> &vec){print(vec.front());for(auto i=vec.begin();++i!=vec.end();){print(' ');print(*i);}return os;}
template<class T,size_t size> inline ostream &operator << (ostream &os,const array<T,size> &vec){print(vec.front());for(auto i=vec.begin();++i!=vec.end();){print(' ');print(*i);}return os;}
template<class T,class L> inline ostream &operator << (ostream &os,const pair<T,L> &p){print(p.first);print(' ');print(p.second);return os;}
template<class T> inline typename enable_if<is_same<T,const char>::value==0,ostream>::type  &operator << (ostream &os,T vec[]){print(*vec);for(auto i=vec;++i!=end(vec);){print(' ');print(*i);}return os;}
template<class T> inline void print(const T &a){cout<<a;}
inline bool out(){printf("\n");return 0;}
template <class Head, class... Tail>
inline bool out(const Head &head,const Tail&... tail){print(head);print(' ');out(tail...);return 0;}
template <class T>
inline void err(T t){cerr<<t<<'\n';}
inline void err(){cerr<<'\n';}
inline bool yes(bool i){return out(i?"yes":"no");}
inline bool Yes(bool i){return out(i?"Yes":"No");}
inline bool YES(bool i){return out(i?"YES":"NO");}
inline bool Yay(bool i){return out(i?"Yay!":":(");}
inline bool Possible(bool i){return out(i?"Possible":"Impossible");}
inline bool POSSIBLE(bool i){return out(i?"POSSIBLE":"IMPOSSIBLE");}
inline void Case(ll i){cout<<"Case #"<<i<<": ";}


ll comb(ll n,ll r){
    ll ans=1;
    rep(r){
        ans*=n-i;
        ans/=i+1;
    }
    return ans;
}
signed main(){
    LL(n,a,b);
    VEC(ll,v,n);
    sort(rrange(v));
    out(sum(v,a)/double(a));
    ll cnt1=0,cnt2=0,i=a-1;
    for(;i>=0&&v[i]==v[a-1];i--)cnt1++;
    for(i++;i<n&&v[i]==v[a-1];i++)cnt2++;
    if(sum(v,a)==v[0]*a){
        ll ans=0;
        rep(i,a,b+1)ans+=comb(cnt2,i);
        out(ans);
    }
    else out(comb(cnt2,cnt1));
}






Compiler output:
a.cc:58:1: error: 'volatile' can only be specified for objects and functions
   58 | volatile struct SETTINGS{SETTINGS(){cout<<fixed<<setprecision(20);};};volatile SETTINGS _SETTINGS();
      | ^~~~~~~~