Submission #801925

#	Time	Username	Problem	Language	Result	Execution time	Memory
801925		fatemetmhr	Seesaw (JOI22_seesaw)	C++17	67 / 100	407 ms	591048 KiB

seesaw

// Be name khode //


#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

#define all(x) x.begin(), x.end()
#define mp     make_pair
#define pb     push_back
#define fi     first
#define se     second

const int maxn5 = 2e3 + 5;

int a[maxn5];

struct kasr{
	__int128 up, dw;
	int l, r;
	kasr(){

	}
	kasr(ll u, ll d){
		up = u;
		dw = d;
	}

} av[maxn5 * maxn5], keep[maxn5][maxn5];

bool operator <(kasr a, kasr b){
	return a.up * b.dw < a.dw * b.up;
}

bool operator <=(kasr a, kasr b){
	return a.up * b.dw <= a.dw * b.up;
}

ld operator -(kasr a, kasr b){
	ld ax = a.up, ay = a.dw, bx = b.up, by = b.dw;
	return ax / ay - bx / by;
}

void out(kasr a){
	cout << ld(a.up) << ' ' << ld(a.dw) << ' ' << ld(a.up) / ld(a.dw) << endl;
}

int main(){
	ios_base::sync_with_stdio(false); cin.tie(0);

	int n; cin >> n;
	ll all = 0;
	int pt = 0;
	for(int i = 0; i < n; i++){
		cin >> a[i];
		all += a[i];
		ll sum = 0;
		for(int j = i; j >= 0; j--){
			sum += a[j];
			av[pt].up = sum;
			av[pt].dw = (i - j + 1);
			av[pt].l = j;
			av[pt].r = i;
			keep[i][j] = av[pt];
			pt++;
		}
	}
	sort(av, av + pt);
	kasr lim(all, n);
	kasr mnr = lim;
	ld ans = 1e18;
	int cnt = 0;
	for(int i = 0; i < pt && av[i] <= lim; i++){
		ans = min(ans, mnr - av[i]);
		//cout << i << ' ' << av[i].l << ' ' << av[i].r << ' ' << ans << endl;
		//out(mnr);
		//out(av[i]);
		int v = av[i].r;
		if(v + 1 < n && mnr < keep[v + 1][av[i].l + 1]){
			mnr = keep[v + 1][av[i].l + 1];
			cnt++;
		}
	}
	assert(cnt <= 10 * n);
	cout << setprecision(15) << ans << endl;
}

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