oj.uz

Submission #877986

# Submission time Handle Problem Language Result Execution time Memory
877986 2023-11-24T01:21:54 Z loncacbuoidai Sure Bet (CEOI17_sure) C++14
100 / 100
 680 ms 3924 KB 
#include <bits/stdc++.h>
using namespace std;

const int N = 1e5 + 5;

int n, k;
double a[N], b[N];

bool check(double f) {
	// cerr << fixed << setprecision(10) << f << '\n';

	int x = ([&] () -> int {
		int l = 1, r = n, ans = n * 3;
		while (l <= r) {
			int mid = (l + r) / 2;
			if ((double)a[mid] - k >= f) {
				ans = mid;
				r = mid - 1;
			} else l = mid + 1;
		}
		return ans;
	}());
	int y = ([&] () -> int {
		int l = 1, r = n, ans = n * 3;
		while (l <= r) {
			int mid = (l + r) / 2;
			if ((double)b[mid] - k >= f) {
				ans = mid;
				r = mid - 1;
			} else l = mid + 1;
		}
		return ans;
	}());
	// cerr << x << ' ' << y << " ok " << (x + y <= k) << '\n';
	return x + y <= k;
}

int32_t main() {
	cin.tie(0)->sync_with_stdio(0);
	if (fopen("OXBET.inp", "r"))
		freopen("OXBET.inp", "r", stdin),
		freopen("OXBET.out", "w", stdout);
	
	cin >> n;
	for (int i = 1; i <= n; i++)
		cin >> a[i] >> b[i];
	
	sort(a + 1, a + n + 1, greater<double>());
	sort(b + 1, b + n + 1, greater<double>());
	for (int i = 1; i <= n; i++)
		a[i] += a[i - 1], b[i] += b[i - 1];
	
	// for (int i = 1; i <= n; i++)
		// cerr << a[i] << ' ' << b[i] << '\n';
	
	// k = 3;
	// check(0.5) << '\n';
	// return 0;
	
	double res = 0;
	for (k = 1; k <= n * 2; k++) {
		// cerr << "k  = " << k << '\n';
		double l = 0, r = 2e8, ans = 0;
		for (int t = 1; t <= 50; t++) {
			double mid = (l + r) / 2;
			if (check(mid)) {
				ans = mid;
				l = mid;
			} else r = mid;
		}
		
		res = max(res, ans);
	}
	
	cout << fixed << setprecision(4) << res;
	
	return 0;
}

Compilation message

sure.cpp: In function 'int32_t main()':
sure.cpp:41:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |   freopen("OXBET.inp", "r", stdin),
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
sure.cpp:42:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |   freopen("OXBET.out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 344 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 4 ms 348 KB Output is correct
13 Correct 4 ms 348 KB Output is correct
14 Correct 4 ms 348 KB Output is correct
15 Correct 4 ms 348 KB Output is correct
16 Correct 4 ms 344 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 344 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 4 ms 348 KB Output is correct
13 Correct 4 ms 348 KB Output is correct
14 Correct 4 ms 348 KB Output is correct
15 Correct 4 ms 348 KB Output is correct
16 Correct 4 ms 344 KB Output is correct
17 Correct 638 ms 3368 KB Output is correct
18 Correct 680 ms 3376 KB Output is correct
19 Correct 644 ms 3372 KB Output is correct
20 Correct 630 ms 3392 KB Output is correct
21 Correct 526 ms 3748 KB Output is correct
22 Correct 640 ms 3372 KB Output is correct
23 Correct 674 ms 3380 KB Output is correct
24 Correct 644 ms 3372 KB Output is correct
25 Correct 627 ms 3156 KB Output is correct
26 Correct 532 ms 3924 KB Output is correct