/* From: "COMPUTATIONAL PHYSICS, 2nd Ed" 
   by RH Landau, MJ Paez, and CC Bordeianu 
   Copyright Wiley-VCH, 2007.
   Electronic Materials copyright: R Landau, Oregon State Univ, 2007;
   MJ Paez, Univ Antioquia, 2007; and CC Bordeianu, Univ Bucharest, 2007.
   Support by National Science Foundation                              
   */     
/*  Coastline.java: Fractal deposition to form "coastline"
          if command line argument, print average height over time
           else; print the coastline itself                       */

import java.util.Random;
import java.io.*;

public class Coastline {
     
  public static void main(String[] args)throws IOException,
                                           FileNotFoundException {
    PrintWriter q = new PrintWriter(
                        new FileOutputStream("coastline.dat"), true);
    boolean printavg = args.length > 0;
    int[] coast = new int[200];
    int i;
    Random random = new Random();
                                             // Deposit particle loop
    for ( i = 0; i < coast.length; i++) coast[i] = 0;
    for ( i = 0; i < 20000; i++) {     // number of particles dropped
      int spot = random.nextInt(200);          // hit edge fills hole
      if (spot == 0) {
        if (coast[spot] < coast[spot+1]) coast[spot] = coast[spot+1];
        else coast[spot]++;
      }
      else if (spot == coast.length - 1) {
        if (coast[spot] < coast[spot-1]) coast[spot] = coast[spot-1];
        else coast[spot]++;
      }
      else if ((coast[spot]<coast[spot-1]) 
                                  && (coast[spot]<coast[spot+1])) {
        if (coast[spot-1] > coast[spot+1]) 
                                        coast[spot] = coast[spot-1];
        else coast[spot] = coast[spot+1];
      }
      else coast[spot]++;
      if (printavg) {                     // Print the average height
        int sum = 0;
        for (int j = 0; j < coast.length; j++) sum += coast[j];
          System.out.println(sum*1./coast.length);    // 1. for float
      }
    }
    if (!printavg)
      for (i = 0; i < coast.length; i++){
        System.out.println(coast[i]);
        q.println(" "+i+" "+coast[i]+" ");
      }
  }
}