Submission #46387

#	Time	Username	Problem	Language	Result	Execution time	Memory
46387		RockyB	Sure Bet (CEOI17_sure)	C++17	100 / 100	431 ms	16880 KiB

sure

/// In The Name Of God
 
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
 
#include <bits/stdc++.h>
 
#define f first
#define s second
 
#define pb push_back
#define pp pop_back
#define mp make_pair
 
#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()
 
#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);
 
#define nl '\n'
#define ioi exit(0);
 
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
 
const int N = (int)5e5 + 7;
const int inf = (int)1e9 + 7;
const int mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;
const ld eps = 1e-4;

const int dx[] = {-1, 0, 1, 0, 1, -1, -1, 1};
const int dy[] = {0, 1, 0, -1, 1, -1, 1, -1};
 
using namespace std;
 
int n;

double a[N], b[N];
double s1[N], s2[N];
 
int main() {
	#ifdef IOI2018
		freopen ("in.txt", "r", stdin);
		freopen ("B.out", "w", stdout);
	#endif
	Kazakhstan
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> a[i] >> b[i];
	}
	sort(a + 1, a + 1 + n);
	sort(b + 1, b + 1 + n);
	for (int i = 1; i <= n; i++) {
		s1[i] = s1[i - 1] + a[n - i + 1];
		s2[i] = s2[i - 1] + b[n - i + 1];
	}
	for (int i = 1; i <= n; i++) {
		s1[i] -= i, s2[i] -= i;
		//cerr << s1[i] << ' ' << s2[i] << nl;
	}
	double ans = 0;
	for (int i = 0; i <= n; i++) {
		double l = 0, r = inf, res = 0;
		for (int t = 1; t <= 200; t++) {
			double x = (l + r) / 2;
			int j = s1[i] - x;
			if (j >= 0 && s2[min(j, n)] - i >= x) res = x, l = x;
			else r = x;
		}
		ans = max(ans, res);
	}
	cout << setprecision(4) << fixed << ans;
	ioi
}

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