Submission #1221202

#	Time	Username	Problem	Language	Result	Execution time	Memory
1221202		boclobanchat	Balloons (CEOI11_bal)	C++20	50 / 100	1208 ms	2712 KiB

bal

#include<bits/stdc++.h>
using namespace std;
vector< pair<double,double> > vi;
double dis(double x1,double y1,double x2,double y2)
{
	return sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
}
double get(pair<double,double> p,double X,double R)
{
	double lt=0,rt=R,ans=0;
	while(rt-lt>1e-5)
	{
		double mid=(lt+rt)/2;
		if(dis(p.first,p.second,X,mid)>=mid+p.second) lt=ans=mid;
		else rt=mid;
	}
	return ans;
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin>>n;
    for(int i=1;i<=n;i++)
    {
    	long long X,R;
    	cin>>X>>R;
    	if(i==1)
    	{
    		cout<<R<<"\n";
    		vi.push_back({X,R});
		}
		else
		{
			double ans=R;
			for(int j=max(0,(int)vi.size()-20);j<vi.size();j++) ans=min(ans,get(vi[j],X,R));
			cout<<setprecision(6)<<fixed<<ans<<"\n";
			while(!vi.empty()&&vi.back().second<=ans) vi.pop_back();
			vi.push_back({X,ans});
		}
	}
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10