#include <stdio.h>
#include <fstream.h>
#include <math.h>

double Cx,Cy,Cz,Nx,Ny,Nz,R,Sx,Sy,Sz,Vx,Vy,Vz;
double A,B,C,D;
double l,m,n;
double x,y,z;
double vec,dist;
double a,b,c,dd,t,t1,t2;

double distance(double x,double y,double z,double x1,double y1,double z1) {
 double rez;
 rez=sqrtl(pow(x-x1,2)+pow(y-y1,2)+pow(z-z1,2));
 return rez;
}

int main()   {
 #ifndef ONLINE_JUDGE
    freopen("1093.in","r",stdin);
    freopen("1093.out","w",stdout);
 #endif
 scanf("%lf %lf %lf",&Cx,&Cy,&Cz);
 scanf("%lf %lf %lf",&Nx,&Ny,&Nz);
 scanf("%lf",&R);
 scanf("%lf %lf %lf",&Sx,&Sy,&Sz);
 scanf("%lf %lf %lf",&Vx,&Vy,&Vz);
 //---------------
 A=Nx;B=Ny;C=Nz;
 D=-(A*Cx+B*Cy+C*Cz);
 //-----------------
 a=-5*C;
 b=A*Vx+B*Vy+C*Vz;
 c=A*Sx+B*Sy+C*Sz+D;
 if (fabs(a)<0.0000001) {
  if (fabs(b)<0.0000001) {printf("MISSED"); return 0;}
  t=-c/b;
  x=Sx+Vx*t;
  y=Sx+Vy*t;
  z=Sx+Vz*t-5*t*t;
    if (distance(x,y,z,Cx,Cy,Cz)<R-0.000001) {printf("HIT"); return 0;}
    else {printf("MISSED"); return 0;}
 }

 dd=b*b-4*a*c;
 if (dd<0) {printf("MISSED");return 0;}

 dd=sqrtl(dd);
 t1=(-b+dd)/(2*a);
 t2=(-b-dd)/(2*a);
 if ((t1<0) && (t2<0)) {printf("MISSED");return 0;}

 //printf("dd=%lf\n",dd);
 //printf("t=%lf\n",t);
 if (t1>=0) {
    x=Sx+Vx*t1;
    y=Sx+Vy*t1;
    z=Sx+Vz*t1-5*t1*t1;
    if (distance(x,y,z,Cx,Cy,Cz)<(R-0.000001)) {printf("HIT"); return 0;}
  }

 if (t2>=0) {
    x=Sx+Vx*t2;
    y=Sx+Vy*t2;
    z=Sx+Vz*t2-5*t2*t2;
    if (distance(x,y,z,Cx,Cy,Cz)<(R-0.000001)) {printf("HIT"); return 0;}
  }

 printf("MISSED");
 return 0;
 #ifndef ONLINE_JUDGE
    fclose(stdin);
    fclose(stdout);
 #endif
}

Maybe anyone knows what the test #3?
Because I cannot find the mistake in my code.

Edited by author 23.06.2005 18:36

When you calculate x,y,z u must use Sx,Sy,Sz but you use only Sx