Submission #468775

#	Time	Username	Problem	Language	Result	Execution time	Memory
468775		DDTerziev04	Mobile (BOI12_mobile)	C++14	100 / 100	554 ms	28460 KiB

mobile

#include<iostream>
#include<cmath>
#include<iomanip>
using namespace std;

const int MAXN=1e6;
const double MAXL=1e10;

pair<long long, long long> pts[MAXN];

bool CanCover(int n, int m, double l)
{
   double d=0;
   for(int i=0; i<n; i++)
   {
      double x=sqrt(l*l-pts[i].second*pts[i].second);
      if(pts[i].first-x<=d && pts[i].first+x>=d)
      {
         d=pts[i].first+x;
      }
   }

   return d>=m;
}

int main()
{
   ios_base::sync_with_stdio(0);
   cin.tie(0);

   int n, m;
   cin >> n >> m;

   for(int i=0; i<n; i++)
   {
      cin >> pts[i].first >> pts[i].second;
   }

   double diff=0.001, l=0, r=MAXL, ans;
   while(r-l>=diff)
   {
      double mid=l+(r-l)/2;
      if(CanCover(n, m, mid))
      {
         ans=mid;
         r=mid;
      }
      else
      {
         l=mid;
      }
   }

   cout << fixed << setprecision(4) << ans << "\n";

   return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
• Subtask 5: 4 / 4
• Subtask 6: 5 / 5
• Subtask 7: 5 / 5
• Subtask 8: 5 / 5
• Subtask 9: 5 / 5
• Subtask 10: 5 / 5
• Subtask 11: 5 / 5
• Subtask 12: 5 / 5
• Subtask 13: 5 / 5
• Subtask 14: 5 / 5
• Subtask 15: 5 / 5
• Subtask 16: 5 / 5
• Subtask 17: 5 / 5
• Subtask 18: 5 / 5
• Subtask 19: 5 / 5
• Subtask 20: 5 / 5
• Subtask 21: 5 / 5