Submission #796719

#	Time	Username	Problem	Language	Result	Execution time	Memory
796719		acatmeowmeow	Sure Bet (CEOI17_sure)	C++11	100 / 100	88 ms	4384 KiB

sure

#include <bits/stdc++.h>

using namespace std;

//#define int long long 

const int N = 1e5;
int n;
double f[N + 5], se[N + 5], prefix[N + 5];

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> f[i] >> se[i];
	sort(f + 1, f + n + 1, greater<double>());
	sort(se + 1, se + n + 1, greater<double>());
	double seValue = se[1];
	for (int i = 1; i <= n; i++, seValue += se[i]) prefix[i] = max(prefix[i - 1], seValue - (double)i);
	double l = -1e9, r = 1e9, ans = -1e9;
	const double eps = 1e-6;
	while (r - l > eps) {
		double m = (l + r)/2.0, fValue = 0.0;
		bool valid = false;
		for (int i = 0; i <= n; i++) {
			fValue += f[i];
			long long rem = min((long long)n, (long long)floor(fValue - m) - i);
			if(rem < 0) continue;
			valid |= prefix[rem] - (double)i > m || abs(prefix[rem] - (double)i - m) < eps;
		}
		if (valid) ans = m, l = m;
		else r = m;
	}
	cout << fixed << setprecision(4) << ans << '\n';
	return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 40 / 40