Submission #607466

#	Time	Username	Problem	Language	Result	Execution time	Memory
607466		UncoolAnon	Sure Bet (CEOI17_sure)	C++14	100 / 100	266 ms	6016 KiB

sure

#include <bits/stdc++.h> 
#define double long double 
using namespace std; 
const double eps=0.00001; 
int main(){
	int n; 
	cin>>n; 
	vector<double> a(n),b(n); 
	for(int i=0;i<n;i++) cin>>a[i]>>b[i]; 
	double answer=0; 
	vector<int> A,B; 
	for(int i=0;i<n;i++){
		if(a[i]<1&&b[i]<1){}
		else{
			A.push_back(i); 
			B.push_back(i); 
		}
	}
	sort(A.begin(),A.end(),[&](int i,int j){
		if(a[i]==a[j]) return b[i]>b[j]; 
		return a[i]>a[j]; 
	}); 
	sort(B.begin(),B.end(),[&](int i,int j){
		if(b[i]==b[j]) return a[i]>a[j]; 
		return b[i]>b[j]; 
	}); 
	double curB=0; 
    n=B.size(); 
	vector<double> p(n); 
	for(int i=0;i<n;i++){
		curB+=b[B[i]]; 
		p[i]=curB-i-1; 
		if(i) p[i]=max(p[i-1],p[i]); 
	}
	double curA=0; 
	for(int i=0;i<n;i++){
		curA+=a[A[i]]; 
		double l=0,r=2e8+1;
		while(r-l>eps){
			double md=(r+l)/2; 
			int j=curA-i-1-md; 
			j=min(j,n); 
			if(j>=1&&p[j-1]-md>=i+1) l=md; 
			else r=md; 
		}
		answer=max(answer,l); 
	}
	cout<<fixed<<setprecision(4)<<answer; 
	return 0; 
}

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