Submission #75823317

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Source Code Expand

#include <bits/stdc++.h>
#pragma warning(disable:4996)
#pragma comment(linker,"/STACK:336777216")
#pragma GCC optimize("03,unroll-loops")
#pragma GCC target("avx,avx2,fma")

using namespace std;
using ll = long long;
using vl = vector<ll>;
using ld = long double;
using pll = pair<ll,ll>;

ll POW(ll a,ll b,ll rem) {
    ll p=1;
    a %= rem;
    for (;b;b>>=1,a=(a*a)%rem) {
        if (b&1)p = (p*a)%rem;
    }
    return p;
}

tuple<ll,ll,ll> extended_gcd(ll a,ll b) {
    if (a==0) return {b,0,1};
    auto [g,x,y] = extended_gcd(b%a,a);
    return {g,y-(b/a)*x,x};
}
ll modinverse(ll a ,ll m) {
    return (get<1>(extended_gcd(a,m))%m+m)%m;
}

void pre() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

void pre2() {
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
}

void presolve() {

}

void solve() {
    ll N;
    cin>>N;
    vl v(N);
    vector<ld> M(N),Mhap(N),MMhap(N);
    for (auto &i:v)cin>>i;
    sort(v.begin(),v.end());

    for (int i=1;i<=N-1;i++) {
        M[i] = M[i-1]+(ld)1/(N-i);
    }
    for (int i=1;i<=N-1;i++) {
        MMhap[i] = MMhap[i-1]+(ld)(N-1)/(N-i);
    }

    ll hap=0;
    for (auto i:v)hap+=i;

    ld cnt=0;
    for (ll i=1;i<=N-1;i++) {
        Mhap[i] = Mhap[i-1] + M[i];
        cnt += Mhap[i];
    }

    ld ans=0;
    for (int i=0;i<N;i++) {
        ans += (ld)(N-i+1) * v[i] / 2;
    }

    if (N==1) {
        cout<<fixed;
        cout.precision(10);
        cout<<ans;
        return;
    }

    cout<<ans<<endl;
    for (int i=1;i<=N;i++) {
        ld tar = (ld)(N-1)*N/2;

        ans += (tar)*v[i-1]/N; // 뒤에 더하는거

        ld newavg = (ld)(hap-v[i-1])/(N-1);

        ld add=-(N-1)+MMhap[N-1];
        ans -= add/N*newavg;

        ld add2 = MMhap[N-1]/(N-1);
        ans -= add2/(N-1)*v[i-1];
    }

    cout<<fixed;
    cout.precision(10);
    cout<<ans;
}

int main() {
    pre();

    presolve();

    ll t=1;
    //cin>>t;
    while (t--) solve();
}

Submission Info

Compile Error

./Main.cpp:2: warning: ignoring '#pragma warning ' [-Wunknown-pragmas]
    2 | #pragma warning(disable:4996)
./Main.cpp:3: warning: ignoring '#pragma comment ' [-Wunknown-pragmas]
    3 | #pragma comment(linker,"/STACK:336777216")

Judge Result