public class QuickSortTest
{  
   // Accepts a random number seed as an optional argument.
   public static void main(String[] args)
   {  
      int[] a;
      QuickSort sorter;
      long seed = System.currentTimeMillis();

      // parse the string argument - if it is a valid long,
      // use it as the random number generator seed value
      try 
      {
	 if ( args.length > 0 )
	    seed = Long.parseLong( args[0] );
      }
      catch ( NumberFormatException exception )
      {
	 System.out.println("Optional argument was not a number.\n"
	    + "Choose a seed for the random number generator.");
      }

      System.out.println("Random array:");
      a = ArrayUtil.randomIntArray(20, 100, seed);
      ArrayUtil.print(a);
      sorter = new QuickSort(a);
      sorter.sort();
      ArrayUtil.print(a);

      System.out.println("\nAlready sorted array:");
      a = ArrayUtil.ascendingIntArray(20);
      ArrayUtil.print(a);
      sorter = new QuickSort(a);
      sorter.sort();
      ArrayUtil.print(a);

      System.out.println("\nReverse sorted array:");
      a = ArrayUtil.descendingIntArray(20);
      ArrayUtil.print(a);
      sorter = new QuickSort(a);
      sorter.sort();
      ArrayUtil.print(a);

      System.out.println("\nArray sorted by halves:");
      a = ArrayUtil.doubleAscendingIntArray(20);
      ArrayUtil.print(a);
      sorter = new QuickSort(a);
      sorter.sort();
      ArrayUtil.print(a);

      System.out.println("\nSorted array except for first element:");
      a = ArrayUtil.firstOutOfOrderIntArray(20);
      ArrayUtil.print(a);
      sorter = new QuickSort(a);
      sorter.sort();
      ArrayUtil.print(a);

      System.out.println("\nArray of mostly equal values:");
      a = ArrayUtil.mostEqualIntArray(20, 100);
      ArrayUtil.print(a);
      sorter = new QuickSort(a);
      sorter.sort();
      ArrayUtil.print(a);

   }
}