class Mean
{

  double calcMean(double[] nums){
    return 20.0;
  }
  
  public static void main(String[] args){
    double[] numbers;
    Mean calculator;
    
    numbers = new double[5];
    
    // Math.random() returns a random double from 0.0 to 1.0
    for(int i = 0; i < numbers.length; i++)
      numbers[i] = Math.random();
    
    // Print the numbers
    for(int i = 0; i < numbers.length; i++)
    System.out.println(i+":\t"+numbers[i]);

    if(args[0].equals("arithmetic"))
      calculator =  new Arithmetic();
    else if(args[0].equals("geometric"))
      calculator =  new Geometric();
    else
      calculator = new Harmonic();
    
    System.out.print("Mean: "+mean(numbers, calculator));
  }
  
  static double mean(double[] nums, Mean cal){
    /*
    if(which_mean.equals("arithmetic"))
      return arithmeticMean(nums);
    else if(which_mean.equals("geometric"))
      return geometricMean(nums);
    else
      return harmonicMean(nums);
    */
    return cal.calcMean(nums);
  }
  
  static double arithmeticMean(double[] nums){
    double agg = 0; // agg stands for aggregate
    for(int i = 0; i < nums.length; i++)
      agg += nums[i];
    return agg/nums.length;
  }

  static double geometricMean(double[] nums){
    double agg = 1.0; // agg stands for aggregate
    for(int i = 0; i < nums.length; i++)
      agg *= nums[i];
    return Math.pow(agg, 1.0/nums.length);
  }

  static double harmonicMean(double[] nums){
    double agg = 0; // agg stands for aggregate
    for(int i = 0; i < nums.length; i++)
      agg += (1/nums[i]);
    return nums.length/agg;
  }
}