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  1. #include<iostream>
  2. #include<cmath>
  3. #include<algorithm>
  4. #include<cstdio>
  5. using namespace std;
  6.  
  7. const double EPS = 1E-7;
  8. int x,y,z,vx,vy,vz;
  9. double bt[100001];
  10. double et[100001];
  11. int main()
  12. {
  13.     int n,r;
  14.         cin>>n>>r;
  15.         for (int i=0;i<n;i++)
  16.         {
  17.                 scanf("%d%d%d",&x,&y,&z);
  18.                 scanf("%d%d%d",&vx,&vy,&vz);
  19.                 double c = 1.0*x*x+1.0*y*y+1.0*z*z-1.0*r*r;
  20.                 double b = 2.0*x*vx+2.0*y*vy+2.0*z*vz;
  21.                 double a = 1.0*vx*vx+1.0*vy*vy+1.0*vz*vz;
  22.                 double d = b*b - 4 * a * c;
  23.                 if (d>-EPS && d<0)
  24.                 {
  25.                         d = 0;
  26.                 }
  27.                 if (d<0)
  28.                         bt[i] = et[i] = 1E100;
  29.                 else
  30.                 {
  31.                         bt[i] = (-b - sqrt(d))/(2*a) - EPS;
  32.                         et[i] = (-b + sqrt(d))/(2*a) + EPS;
  33.                 }
  34.         }
  35.         sort(bt,bt+n);
  36.         sort(et,et+n);
  37.  
  38.         int m;
  39.         cin>>m;
  40.         int t;
  41.         for (int i=0;i<m;i++)
  42.         {
  43.                 cin>>t;
  44.                 int bc = lower_bound(bt,bt+n,(double)t) - bt;
  45.                 int ec = lower_bound(et,et+n,(double)t) - et;
  46.                 cout<<bc-ec<<endl;
  47.         }
  48.  
  49.         return 0;
  50. }
  51.  
Success #stdin #stdout 0s 4464KB
comments (?)
stdin
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5 7
-5 2 0 -1 0 0
1 -3 2 -2 2 0
-3 -4 0 0 -2 -1
4 2 4 -1 -1 2
1 0 4 -1 1 1
6
0
1
2
3
4
5
stdout
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5
5
2
1
0
0
https://ideone.com/Uw0rVr
language:
C++ (gcc 8.3)
created:
11 years ago
visibility:
public

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