Thread: Debugging help :(

I just want to create a simple code of a moving ball colldiing to each other. I am able to print the results, however, my fprintf isn't working . I am quite new to this, so please help? Thank you in advance.

After running it just says "EASY.exe has stopped working..."

My compiler didnt show where the error either.

Code:

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


typedef double real;


typedef struct
{
    real xpos;
    real ypos;
    real zpos;
    
    real uvel;
    real vvel;
    real wvel;
    
    real omegax;
    real omegay;
    real omegaz;
    
    real radius;
    real mass;
    
} sphere;


void update_position(sphere *ball, real dt)
{
   //(*ball).xpos 
   ball->xpos=ball->xpos + dt*ball->vvel;
   //ypos,zpos   
}


void detect_ball(sphere *ball1, sphere *ball2, real *pdist)
{
    
    *pdist=sqrt((ball2->xpos-ball1->xpos)*(ball2->xpos-ball1->xpos)+
               (ball2->ypos-ball1->ypos)*(ball2->ypos-ball1->ypos));
               
//        if ( dist<= (ball1->radius + ball2->radius) +0.0075 )
//        {
//            if ( dist>= ball1->radius + ball2->radius -0.0075   )
//            {   
//            *ptime=0;
//            }
//        }


}


int main(int argc, char *argv)
{
    real dt=0.01;
    real t, dist1, tmax=1, mlimit, firstvvel, gap=1.5,  dist[2], ballmatxpos[101][2];
    int nballs=1 ;
    int i,j,m,k;
    sphere *ball;
    
    ball=(sphere *)malloc(nballs*sizeof(sphere));
    mlimit=tmax/dt;
    //initialise positions
    for(i=0;i<=nballs;i++)
    {
       ball[i].radius=0.5;
       ball[i].xpos=(real) i * (2*ball[i].radius + gap);
       ball[i].ypos=0.0;  
       
       ball[i].uvel=1.0;
       ball[0].vvel=1.0; 
       ball[1].vvel=0.0; 
    }
    
    //pendulum to be released
   // ball[0].xpos=0;
    //ball[0].ypos=0;
  //  firstvvel=0;
    
    //timestep loop
    t=0.0;
    dist1=0.0;
    while(t<tmax)
    {
        for(m=0;m<=mlimit;m++)
       {
       //update position
        for(i=0;i<=nballs;i++)
        {
              update_position(&(ball[i]), dt);  
        }
       //collision detection
        for(i=0;i<=nballs;i++)
        {
            for(j=0;j<=nballs;j++)
            {
                detect_ball(&(ball[i]),&(ball[j]), &dist1);      
                             
              if ( dist1 <= (ball[i].radius + ball[j].radius) +0.075 )
                {
                   if ( dist1 >= (ball[i].radius + ball[j].radius) -0.075   )
                    {
             //  ball2->uvel=ball1->vvel;
                //yes collision, modify velocities and rotation rates   
                    t=0;
                     }
                }
            }
        }
        
        ballmatxpos[m][0]=t;
        ballmatxpos[m][1]=ball[0].xpos;


   printf("In this case, initial velocity= %3.4lf with t=%3.4lf \n", ballmatxpos[m][0], t );   
                               
        t+=dt;    
        }
    }
    


//    ---------------//-------------------------
      FILE *pFile1;
         FILE *pFile2;
         pFile1 = fopen("graphing3.txt", "w");
         pFile2 = fopen("graphing4.txt", "w");
         if (pFile1 != NULL)
        {
             for(m=0;m<=mlimit;m++)
             {
         fprintf( pFile1, " %3.4lf \n ", ballmatxpos[m][0]);
              } 
      fprintf( pFile1,"\n");
      fclose(pFile1); 
        }
      if (pFile2 != NULL)
        {
             for(m=0;m<=mlimit;m++)
             {
         fprintf( pFile2, " %3.4lf  \n", ballmatxpos[m][1]);
         }
       fprintf( pFile2,"\n");
      fclose(pFile2);      
       }  
                 else
        {
            printf("inda dapat print bro");
       }






//  -----------------------------------------------------  




    
    getch();
    return 0;
}