import java.util.*;
public class outliers
{
    public static void main(String[] args)
    {
        Scanner kbd = new Scanner(System.in);
        System.out.print("Enter the number of randomly generated data points \n (an outlier will be created every ten data points): ");
        int arraySize = kbd.nextInt();
        double[] data = getArray(arraySize);

        double[] arrayNew = new double[data.length];

        double q1 = 0, q3 = 0, IQR, lowerFence, upperFence, median;

        median = median(data);

        System.out.println("Original Data set: ");
        printArray(data);

        Arrays.sort(data);
        System.out.println("Sorted Data set: ");
        printArray(data);

        if (median % 2 == 0) //Finds the lower and upper quartiles
        {
            q1 = data[(int)(median/2)];
            q3 = data[(int)(median * 1.5)];
        }
        else
        {
            q1 = data[(int)(median/2)-1];
            q3 = data[(int)(median * 1.5)+1];
        }

        IQR = q3 - q1; //Calculates IQR

        lowerFence = q1 - 3 * IQR; //Calculates lower and upper fences
        upperFence = q3 + 3 * IQR;

        arrayNew = removeOutliers(data, lowerFence, upperFence);

        System.out.println("Data set with outliers removed:");
        printArray(arrayNew);
    }
    public static void printArray(double[] data)
    {

        System.out.println("=========================================================================");
        for(int n = 0; n <= data.length - 1; n++)
        {
            if(data[n] == 0) //Ignores empty slots
            {
            }
            else
            {
                if((n + 1)%10 == 0) //Prints new line every ten data points
                {
                    System.out.printf(" %6.2f", data[n]);
                    System.out.println();
                }
                else
                    System.out.printf(" %6.2f", data[n]);
            }
        }
        System.out.println();
        System.out.println("=========================================================================");
        System.out.println();

        return;
    }
    public static double median(double[] data)
    {
        double median;

        if (data.length%2 == 0)
            median = data.length/2;
        else
            median = data.length/2 - 1;

        return median;
    }
    public static double[] removeOutliers(double[] data, double lFence, double uFence)
    {
        double[] arrayNew = new double[data.length];
        int count = 0; //Counts the data points in arrayRevised
        System.out.println();
        for (int n = 0; n < data.length; n++) {
            if (data[n] > lFence && data[n] < uFence) {
                arrayNew[count] = data[n]; //Adds data points that aren't outliers to the new array
                count ++;
            }
            else {
               System.out.printf("%6.2f is an outlier. \n", data[n]);
            }
        }
        System.out.println();

        return arrayNew;
    }
    public static double[] getArray(int length)
    {
        double[] data = new double[length];
        for(int n = 0; n < data.length; n++)
        {
            if(n%10 == 0)
                data[n] = Math.random()*2000 - 1000;
            else
                data[n] = Math.random()*100;
        }
        return data;
    }
}