import javax.swing.JOptionPane;
import java.util.*;

public class Array2


{
    public static void main(String[]args)
    {
       int students;
       String again;  
       int [ ] scores = new int[10];
       String numOfStudents;
       String posNumber;
       String inputOrRandom=null;
       String answer;
      
       do
       {
        numOfStudents = JOptionPane.showInputDialog("How many students in the class?");
        students = Integer.parseInt(numOfStudents);
        
        while(students < 0)
        {
            posNumber = JOptionPane.showInputDialog("Please enter a positive number.");
            students = Integer.parseInt(posNumber);
        }
            if(students > 0)
            inputOrRandom = JOptionPane.showInputDialog("Would you like to input the numbers or have them random generate? (I/R) ");
            
            if(inputOrRandom.equals("I") || inputOrRandom.equals("i"))
             scores = generateUser(students);
                        
            else if
            (inputOrRandom.equals("R") || inputOrRandom.equals("r"))
            scores = generateRandom(students);
            
            else
            return;
            
            outputHistogram(scores);
            
            again = JOptionPane.showInputDialog("Would you like to try again? ");
        }
            while(again.equals("N") || again.equals("n"));                                              
            System.out.println("");//if(again =="N" || again =="n")
            System.exit(0);
            
        }

    public static int [] generateUser(int numOfStudents)
    {
        int i=0;
        int [ ] scores = new int[10];
        int grade;
        
       for(int j = 0; j < 10;++j)
            scores[j] = 0;
          
        for(i = 0; i < numOfStudents; i++)
        {
                do
            {
             grade = Integer.parseInt(JOptionPane.showInputDialog(
                    "enter score from 1 to 100 inclusive"));
            }while(grade < 1 || grade >100);    //if the user enters a score <1 or > 100 it loops back up and
                                                //increment the counter.
                    
            scores[(grade-1)/10]= scores[(grade-1)/10]+1;
            System.out.print(grade + " ");
        }
            System.out.println();
            return scores;
    }
    
    public static int[] generateRandom(int numOfStudents)
    {
            int[] scores = new int[10];
            Random generator = new Random();
        
            for(int i = 0; i < numOfStudents; i++) {
            int grade = 0;
            while(grade < 1 || grade > 100) {
               double x = generator.nextGaussian();
               x += 3.6;
               x *= 20;
               grade = (int) x;
               grade = Math.max(1,grade);
               grade = Math.min(100,grade);
            }
                      scores[(grade-1)/10]++;
                      System.out.print(grade + " ");
        }
            System.out.println();    
            return scores;
    }

    public static void outputHistogram(int [] scores)
    {
            
             for(int i = 0; i < 10;++i)
             {
               if(i == 0)
              
               System.out.print((i*10 + 1)+" -"+(i*10+10)+ "  |"); //this prints the labels 1-10
               if(i >= 1 && i <= 8)
               System.out.print((i*10 + 1)+"-"+(i*10+10)+ "  |");//this prints the labels 11-21 thru 81-90.
               if(i >= 9 && i <= 10)  // else
               System.out.print((i*10 + 1)+"-"+(i*10+10)+ " |");//this prints the labels 91-100.
                                  
               for(int x =0; x < scores[i];++x)
               System.out.print("*");               //this prints the astriks
                
               System.out.println();
             }
          
    }
}

private void AddEntryJButtonActionPerformed( ActionEvent event )
{
    int answer = JOptionPane.YES_OPTION;
    int count = 0;
  
   try{
  
    
        while (answer == JOptionPane.YES_OPTION )
            {

            String ar = JOptionPane.showInputDialog("Please, enter artist name");
            String cd = JOptionPane.showInputDialog("Enter CD name:");
            int n = getNumberOfTracks();
            if(n < 0)
            {
                    // user cancelled
                continue;
            }

              if  (ar!=null &&  cd!=null && !ar.trim().equals("") && !cd.trim().equals(""))
                 //making sure that data has been inputted
                {
                Album album = new Album(ar, cd, n);    //creating new Album object and adding my three variables to it
                list.add(album);  //adding this Album object to my ArrayList
                }
                
            else
                {
                   JOptionPane.showMessageDialog(null, "please enter all required data");
                }
    
        answer = JOptionPane.showConfirmDialog(null, "Enter another record?",  //if yes, will loop again, if no it will exit
                      "???", JOptionPane.YES_NO_OPTION);
    
        count++; //increment
    
            }
       }
      
   catch (NumberFormatException  e)
        {
            System.err.println("Caught NumberFormatException : "+ e.getMessage());
            e.printStackTrace();

        }
        

}