Submission #842596

#	Time	Username	Problem	Language	Result	Execution time	Memory
842596		vjudge1	Sure Bet (CEOI17_sure)	C++17	100 / 100	76 ms	11476 KiB

sure

#include <bits/stdc++.h>
using namespace std;

const int N = 1e6 + 5;

double pre_a[N];
double pre_b[N];
double a[N] , b[N] , mx[N];

main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	if(fopen("solve.inp" , "r")) {
		freopen("solve.inp" , "r" , stdin);
		freopen("solve.out" , "w" , stdout);
	}
	int n;
	cin >> n;
	for(int i = 0; i < n; i++) {
		cin >> a[i] >> b[i];
	}
	sort(a , a + n , greater <double> ());
	sort(b , b + n , greater <double> ());
	for(int i = 1; i <= n; i++) {
		pre_a[i] = pre_a[i - 1] + a[i - 1] - 1;
		pre_b[i] = pre_b[i - 1] + b[i - 1] - 1;
	}
	for(int i = 1; i <= n; i++) {
		mx[i] = max(mx[i - 1] , pre_b[i]);
	}
	double l = 0.0;
	double r = INT_MAX;
	for(int i = 0; i < 100; i++) {
		double mid = (l + r) / 2;
		bool check = false;
		for(int j = 0; j <= n; j++) {
			int x = min(n * 1.0 , (pre_a[j] - mid));
			if(x >= 0 && mx[x] >= j + mid) {
				check = (check | x);
			}
		}
		if(check == true) l = mid;
		else r = mid;
	}
	cout << setprecision(4) << fixed << r << '\n';
	return 0x0;
}

Compilation message (stderr)

sure.cpp:10:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   10 | main() {
      | ^~~~
sure.cpp: In function 'int main()':
sure.cpp:14:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |   freopen("solve.inp" , "r" , stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
sure.cpp:15:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |   freopen("solve.out" , "w" , stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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