HeadsOrTails.java

import java.util.ArrayList;
import java.util.List;
/*
 *     __  __               __     ____      ______      _ __    
 *    / / / /__  ____ _____/ /____/ __ \____/_  __/___ _(_) /____
 *   / /_/ / _ \/ __ `/ __  / ___/ / / / ___// / / __ `/ / / ___/
 *  / __  /  __/ /_/ / /_/ (__  ) /_/ / /   / / / /_/ / / (__  ) 
 * /_/ /_/\___/\__,_/\__,_/____/\____/_/   /_/  \__,_/_/_/____/  
 * https://github.com/guyhughes
 */
class HeadsOrTails {
  public static final int ITERATIONS = 100000;
  public static void main(String[] args){
    long start;
    double head_time,tail_time;
    ArrayList<Integer> a = new ArrayList<>();
    System.out.printf("Iterations: %s\n",ITERATIONS);
    start = System.currentTimeMillis();
    for(int x=0; x < ITERATIONS; x++)
      a.add(new Integer(0));
    tail_time = (System.currentTimeMillis()-start)/1000.0;
    System.out.printf("Adding to tail took %,5.4fs\n",tail_time);
    start = System.currentTimeMillis();
    a.clear();
    for(int x=0; x < ITERATIONS; x++)
      a.add(0,new Integer(0));
    head_time = (System.currentTimeMillis()-start)/1000.0;
    System.out.printf("Adding to head took %,5.4fs\n",head_time);
    System.out.printf("Therefore adding to tail was %,5.2fx faster than adding to head for %d iterations.\n",head_time/tail_time,ITERATIONS);
  }
}