import awb.*;
import java.awt.*;
import java.awt.event.*;

public class ArrayStats extends java.applet.Applet implements ActionListener
{
    TextField mInstruct, mAnswer;
    IntField iCount;                                      
    double list[];
    Button bStore, bShow, bExtremes, bMean, bClear;
    int count, nextFree, nextUse;

    double mean(double[] list, int size)
    {
        int k = 0;
	double sum = 0.0;
        
	while (k < size)
	{
	    sum = sum + list[k];
	    k = k + 1;
	}
	return sum/size;
    }
   
    double max(double[] list, int size)
    {
        int k = 1;
	double largest = list[0];
        
	while (k < size)
	{
	    if (list[k] > largest)
            {
                largest = list[k];
	    }
	    k = k + 1;
	}
	return largest;
    }
   
    double min(double[] list, int size)
    {
        int k = 1;
	double smallest = list[0];
        
	while (k < size)
	{
	    if (list[k] < smallest)
            {
                smallest = list[k];
	    }
	    k = k + 1;
	}
	return smallest;
    }
   
    public void init()
    {   
        list = new double[100];
        mInstruct = new TextField(70);
        mAnswer = new TextField(70);
        mInstruct.setText("Enter Value, then press Store button");
        iCount = new IntField(10);
        bStore = new Button("Store");
        bShow = new Button("Show");
        bExtremes = new Button("Extremes");
        bMean = new Button("Mean");
        bClear = new Button("Clear");
	nextFree = 0;
        nextUse = 0;
        
        bStore.addActionListener(this);
        bShow.addActionListener(this);
        bExtremes.addActionListener(this);
        bMean.addActionListener(this);
        bClear.addActionListener(this);

        add(mInstruct);
        add(iCount);
        add(bStore);
        add(bShow);
        add(bExtremes);
        add(bMean);
        add(bClear);
        add(mAnswer);
    }           
        
    public void actionPerformed(ActionEvent event)
    {
        int value, total;;
        Object cause = event.getSource();
        
        if (cause == bStore)
        {
            value = iCount.getInt();
            list[nextFree] = value;
            nextFree = nextFree + 1;
            iCount.setInt();     // clear IntField
        }
        if (cause == bShow)
        {
            mAnswer.setText("The value in element "+nextUse+" is "+
                               list[nextUse]);
	    nextUse = (nextUse + 1)% nextFree;
        }
        if (cause == bExtremes)
        {
            mAnswer.setText("The largest data item is " + max(list, nextFree)
		     + " and the smallest data item is " + min(list, nextFree));
        }
        if (cause == bMean)
        {
            mAnswer.setText("The average is " + mean(list, nextFree));
        }
        if (cause == bClear)
        {
            nextUse = 0;
            nextFree = 0;
            mAnswer.setText("The old data has been cleared out");
        }
    }
}