fork(1) download 
  1. #pragma GCC optimized("-O3")
  2. #include<bits/stdc++.h>
  3. using namespace std;
  4. #define ll long long
  5. #define ld long double
  6. #define lf __float128
  7. #define pb push_back
  8. #define x first
  9. #define y second
  10. int n;
  11. const int N=2e5+5;
  12. ld x[N],y[N];
  13. ld efs=1e-15;
  14. bool f(lf r){
  15.     ld minx,maxx; 
  16.     minx=-1e12,maxx=1e12;
  17.     int i;
  18.     for(i=1;i<=n;i++){
  19.         lf val;
  20.         val=fabs((ld)r-y[i]);
  21.         if(y[i]>r+r)
  22.             return 0;
  23.         ld temp;
  24.         temp=((r*r)-(val*val));
  25.         temp=sqrt(temp);
  26.         minx=max(minx,x[i]-temp);
  27.         maxx=min(maxx,x[i]+temp);
  28.     }
  29.     return minx<=(maxx+efs);
  30. }
  31. int main(){
  32.     ios::sync_with_stdio(false);
  33.     cin.tie(0);
  34.     cout.tie(0);
  35.     int i;
  36.     //assert(freopen("input.txt","r",stdin));
  37.     //assert(freopen("output.txt","w",stdout));
  38.     cin>>n;
  39.     int f1=0,f2=0;
  40.     for(i=1;i<=n;i++){
  41.         cin>>x[i]>>y[i];
  42.         if(y[i]<0)
  43.             f2++;
  44.         if(y[i]>0)
  45.             f1++;
  46.         y[i]=fabs(y[i]);
  47.     }
  48.     //cout<<f1<<" "<<f2;
  49.     if(f1*f2){
  50.         cout<<-1;
  51.         return 0;
  52.     }
  53.     ld l=0,r=1e18;
  54.     //cout<<f(0);
  55.     for(i=(n>100?55:200);i;i--){
  56.         lf mid;
  57.         mid=(l+r)/2;
  58.         if(f(mid))
  59.             r=mid;
  60.         else
  61.             l=mid;
  62.     }
  63.     cout<<fixed<<setprecision(20);
  64.     cout<<(l+r)/2;
  65.     return 0;
  66. }
Success #stdin #stdout 0s 21488KB
comments (?)
stdin 
20

7571542 9868879

3634934 5986987

2297651 5538795

9701582 8250721

-2913168 4968483

8838674 5771883

-3348778 8326335

-577797 750161

-7223138 9113512

-1808146 6044926

-756446 417388

4700417 1550148

-5568937 20029

-9170707 6103893

7445655 7161843

8820510 4145867

-4466974 9280518

5842792 1905697

-8784063 3253524

-796596 1060279
stdout 
28974952.66802237000229069963
https://ideone.com/8YBNJ6
language:
C++14 (gcc 8.3)
created:
6 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!