/* 
************************************************************************
*  film.c: Ballistic deposition simulation (fractal)                   *
*                      *
*  From: "A SURVEY OF COMPUTATIONAL PHYSICS" 
   by RH Landau, MJ Paez, and CC BORDEIANU 
   Copyright Princeton University Press, Princeton, 2008.
   Electronic Materials copyright: R Landau, Oregon State Univ, 2008;
   MJ Paez, Univ Antioquia, 2008; & CC BORDEIANU, Univ Bucharest, 2008
   Support by National Science Foundation                              
*                                                                      *
*  comment: If your compiler complains about drand48, srand48          *
*           uncomment the define statements further down               *
*           Plot data without connecting datapoints with lines         *
************************************************************************
*/   
#include <stdio.h>
#include <stdlib.h>

/* if you don't have drand48 uncomment the following two lines */
/*    #define drand48 1.0/RAND_MAX*rand 
      #define srand48 srand                */   
      
#define max 30000   /* number of iterations */
#define seed 68111    /* seed for number generator */
    
main() 
{    
   int i, hit[200], r;
                               
   FILE *output;      /* save data in film.dat */
   output = fopen("film.dat","w");
   
   srand48(seed);
   
   for (i=0; i<200; i++) hit[i] = 0;    /* clear array */  
   
   for(i=1; i<=max; i++)
   {
      r = (int)(199*drand48());     /* r=0..199 */
      
      if((hit[r] >= hit[r-1]) && (hit[r] >= hit[r+1]))
      {
         hit[r]++;
      }
      else if(hit[r-1] > hit[r+1])
      {
         hit[r] = hit[r-1];
      }
      else
      {   
         hit[r] = hit[r+1];  
      }
      fprintf(output, "%d\t%d\n", r, hit[r]);
   }
   printf("data stored in film.dat\n");
   fclose(output);
}