class ArrayStats {

   /*
    * Find the maximum of an integer array
    */
   static int max(int[] a) {
      assert a != null : "Null array passed to max";
      assert a.length > 0 : "Empty array passed to max";
      int biggest = a[0];
      for (int n: a)
         if (n > biggest)
            biggest = n;
      return biggest;
   }

   /*
    * Find the sum of an integer array
    */
   static int sum(int[] a) {
      assert a != null : "Null array passed to sum";
      assert a.length > 0 : "Empty array passed to sum";
      int sum = 0;
      for (int n: a)
         sum += n;
      return sum;
   }

   /* 
    * Find the average of an integer array
    */
   static double average(int[] a) {
      assert a != null : "Null array passed to average";
      assert a.length > 0 : "Empty array passed to average";
      return (double)sum(a) / (double)a.length;
   }

   /*
    * Driver to test the above methods
    */      
   public static void main(String[] args) {
      int[] numbers = {29, 47, -8, 51, 13};
      System.out.print("List: ");
      for (int n: numbers) System.out.print(n + " ");
      System.out.println();
      System.out.println("Max = " + max(numbers));
      System.out.println("Sum = " + sum(numbers));
      System.out.println("Average = " + average(numbers));
   }
}  // end of ArrayStats class