Submission #633049

#	Time	Username	Problem	Language	Result	Execution time	Memory
633049		iomoon191	Seesaw (JOI22_seesaw)	C++17	0 / 100	1 ms	212 KiB

seesaw

#include<bits/stdc++.h>
// #define int long long
#define all(a) (a).begin(), (a).end()
#define sz(a) (int)(a).size()
#define pb push_back
#define eb emplace_back
#define For(i,a,b) for(int i=(a); i<=(b); ++i)
#define roF(i,a,b) for(int i=(a); i>=(b); --i)
#define fi first
#define se second
#define mod 998244353
using namespace std;
// using namespace atcoder;
#ifdef DEBUG__
struct db_os{
    ostream& os;
    bool chk;
    template<class T> auto operator<<(T&& x){
        if(!chk) os << ", ";
        chk=0;
        os << x;
        return *this;
    }
};
template<class... T> void db_out(T&&... t){
    (db_os{cerr, 1} << ... << t);
}
#define dbg(...)                                       \
    do{                                                 \
        cerr << __LINE__ << ":" << #__VA_ARGS__ << "=";  \
        db_out(__VA_ARGS__);                              \
        cerr << "\n";                                      \
    }while(0);
#else
#define dbg(...)
#endif
typedef vector<int> vi;
typedef pair<int, int> pi;
typedef long long ll;
typedef long double ld;
const int N=100005;
const ll inf=0x3f3f3f3f;
mt19937 rng(random_device {}()); 
int rand(int a){
    return rng()%a;
}
int n, pref[N];
double cal(int l, int r){
    return 1.0*(pref[r]-pref[l-1])/(r-l+1);
}
void rmain(){
    cin >> n;
    For(i,0,n-1){
        int x; cin >> x;
        pref[i+1]=pref[i]+x;
    }
    vector<pair<double, double>> vc(n);
    double avg=1.0*pref[n]/n;
    For(i,0,n-2){
        int l=0, r=n-i-1;
        while(l < r){
            int mid=(l+r+1) >> 1;
            if(cal(mid+1, mid+i+1) <= avg) l=mid;
            else r=mid-1;
        }
        vc[i].fi=cal(l+1, l+i+1);
        vc[i].se=cal(l+2, l+i+2);
    }
    vc[n-1].fi=vc[n-1].se=avg;
    sort(all(vc));
    double res=inf, mx=-inf;
    For(i,0,n-1){
        res=min(res, max(mx, avg)-vc[i].fi);
        mx=max(mx, vc[i].se);
    }
    cout << fixed << setprecision(50) << res;
}

signed main(int argc, char *argv[]){
    iostream::sync_with_stdio(0);
    int T=1;
    while(T--) rmain();
    return 0;
}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 33
• Subtask 3: 0 / 33
• Subtask 4: 0 / 33