// File   : flow-loops/MaxMinAvgIncome.java
// Purpose: Calculates income statistics.  Illustrates:
//          * Running calculation of minimum and maximum.
//          * Initializing min and max values to largest/smallest
//            possible values.  Alternative is to use first value.
//          * Reads until non-number / EOF.
//            Alternative is read until sentinel value.
//          * Average is total divided by number of values.
// Name   : Fred Swartz - 2006-Dec-14 - Placed in public domain.

import java.util.*;

public class MaxMinAvgIncomeS {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        //... These variables hold the max and min incomes.
        double maxIncome = Double.MIN_VALUE; // Maximum income.    //Note 1
        double minIncome = Double.MAX_VALUE; // Minimum income.

        //... These variables are used to compute the average.
        int    count       = 0;              // Number of input values.
        double totalIncome = 0;              // Total of all incomes.

        //... Loop until negative number is entered.
        System.out.println("Enter incomes.  Terminate with EOF or non-number.");
        while (input.hasNextDouble()) { 
            //... Get the next value.
            double income = input.nextDouble();
            
            //... Compare this value to max and min. Replace if needed.
            if (income > maxIncome) {
                maxIncome = income;
            }
            if (income < minIncome) {
                minIncome = income;
            }

            //... Keep track of these values for average calculation.
            count++;                 // Count the number of data points.
            totalIncome += income;   // Keep a running total.
        }

        //... Be sure user entered at least one data point.
        if (count > 0) {                                          //Note 2
            //... Display statistics
            double average = totalIncome / count;
            System.out.println("Number of values = " + count);
            System.out.println("Maximum = "  + maxIncome);
            System.out.println("Minimum = "  + minIncome);
            System.out.println("Average = "  + average);
        } else {
            System.out.println("Error: You entered no data!");
        }
    }
}