Submission #998470

#	Time	Username	Problem	Language	Result	Execution time	Memory
998470		hippo123	Balloons (CEOI11_bal)	C++17	10 / 100	491 ms	12624 KiB

bal

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

#define pr pair<double, double>
#define ll long long
#define pb push_back
#define f first
#define s second
vector<double> x, r;
vector<pr> xr;

bool check(double mid, int bb, int be){
	
	bool judge=false;
	for (int i=bb; i<be; i++){
		double rr=(mid+r[xr[bb].s])*(mid+r[xr[bb].s]);
		
		double dist1=(mid-r[xr[bb].s])*(mid-r[xr[bb].s])+(x[be]-x[xr[bb].s])*(x[be]-x[xr[bb].s]);
		//cout<<" r[be]/r[[xr[bb].s]= "<<r[be]<<" "<<r[xr[bb].s]<<endl;
		//cout<<" rr/dist1 "<<rr<<" "<<dist1<<endl;
		if(rr>=dist1){
			judge=true; break;
		}
	} 	
	return judge;
		
}
	

int main(){
	int n; cin>>n;
	x.resize(n); r.resize(n); xr.resize(n);
	for (int i=0; i<n; i++) {
		cin>>x[i]>>r[i];
		xr[i].f=x[i]+r[i]; xr[i].s=i; 
	}
	
	vector<double> ans(n);
	for (int i=0; i<n; i++){
		if(i==0) {
			ans[i]=r[i]; 
			continue;
		}
		//
		pr node={x[i]-r[i], 0};
		int pos=lower_bound(xr.begin(), xr.begin()+n, node)-xr.begin(); 
		//cout<<" i= "<<i<<endl;
		//cout<<" pos= "<<pos<<endl;
		if(pos==i) {ans[i]=r[i]; continue;}
		
		double lft=0; double rht=r[i]; 
		while(rht-lft>0.00001){
			double mid=lft+(rht-lft)/2;
			//cout<<" lft/rht/mid= "<<lft<<" "<<rht<<" "<<mid<<endl;
			
			if(check(mid, pos, i)) {
				rht=mid;
			}
			else lft=mid;			
			
		}
		ans[i]=lft;
	}
	cout << fixed <<setprecision(3);
	for (int i=0; i<n; i++) cout<<ans[i]<<endl;
}

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