what is the rong

Write a JAVA program to auto-grade exams. For a class of N students, your program should read letter answers (A, B, C, D) for each student. Assume there are 5 questions in the test. Your program should finally print the grade percentage (out of 100%) of each student, and also the class average. Define the exam answer key as Final Array in your program.

i want to know what is the wrong with this program......without changing the style of the code

public class Main {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    double totalpercentage = 0.00;
    double average = 0.00;
    char array[] = { 'a' , 'a' , 'a' , 'a' , 'b' };
    char arr[] = new char[array.length];
    Scanner numofstudents = new Scanner (System.in);
    System.out.println(" Enter number of students ");
    int students = numofstudents.nextInt();



        for ( int i=0; i < students; i++ ){

            for ( int j = i; j <= array.length; j++ ){

            int count = 0;
            arr[j] =(char) Integer.parseInt(JOptionPane.showInputDialog(" enter the answers " + j));

         double percentage =  ( (count /5.0)*100 );
        System.out.println(" Percentage is " + percentage + "%" );

        totalpercentage = totalpercentage + percentage;
            }
        }

        average = totalpercentage / students;
    System.out.println(" class average is " + average + "%");


    }

}