public void addStudent(Student student)
{
  resizeIfFull();
  studentArray[numStudents] = student;
  numStudents++;
}



public int getGradeForStudentWithName(String name)  //assume no duplicate names. return -1 if no such student
{
  for(int i = 0; i < numStudents; i++)
  {
    String n = studentArray[i].getName();
    if(n.equals(name))
      return studentArray[i].getGrade();
  }
  return -1;
}



public String nameOfStudentWithHighestGrade()  //assume no duplicate names, and at least 1 student
{
  int max = studentArray[0].getGrade();
  int indexOfMax = 0;
  
  for(int i = 1; i < numStudents; i++)
  {
    if (studentArray[i].getGrade() > max)
    {
      max = studentArray[i].getGrade();
      indexOfMax = i;
    }
  }
  return studentArray[indexOfMax].getName();
}



public void increaseAllGradesBy(int bonus)  //up to a max grade of 100
{
  for(int i = 0; i < numStudents; i++)
  {
    int grade = studentArray[i].getGrade() + bonus;
    if (grade > 100)
      grade = 100;
    studentArray[i].setGrade(grade);
  }
}



public boolean hasStudentWithGrade(int grade)
{
  for(int i = 0; i < numStudents; i++)
  {
    if (grade == studentArray[i].getGrade())
      return true;
  }
  return false;
}



public int countStudentsWithNamesOfLength(int length)
{
  int count = 0;
  for(int i = 0; i < numStudents; i++)
  {
    int x = studentArray[i].getName().length();
    if (x == length)
      count++;
  }
  return count;
}



public double averageGradeForSection(char section)  //assume at least 1 student
{
  int numInSection = 0; //keeps track of total number of students in the section
  int runningTotal = 0; //keeps track of the grade total in the section 
  for(int i = 0; i < numStudents; i++)
  {
    if(studentArray[i].getSection() == section)
    {
      runningTotal += studentArray[i].getGrade();
      numInSection++;
    }
  }
  double ave = (double)(runningTotal) / (double)(numInSection);
  return ave;
  
}



public Roster makeRosterForStudentsInSection(char section)
{
  Roster r = new Roster();
  for(int i = 0; i < numStudents; i++)
  {
    if(studentArray[i].getSection() == section)
    {
      r.addStudent(studentArray[i]); 
    }
  }
  return r;
}



public void moveLastStudentToFrontWithoutChangingOrder()  //e.g. ABCDE -> EABCD.  assume numStudents > 0
{
  Student last = studentArray[numStudents - 1];
  for (int i = numStudents - 1; i > 0; i--)
  {
    studentArray[i] = studentArray[i-1]; 
  }
  studentArray[0] = last;
}



public void removeStudentWithoutChangingOrder(String name)  //assume no more than one student with this name
{
  for(int i = 0; i < numStudents; i++)
  {
    if (studentArray[i].getName().equals(name))
    {
      for (int to = i; to < numStudents - 1; to++)
      {
        studentArray[to] = studentArray[to + 1];
      }
      studentArray[numStudents-1] = null;
      numStudents--;
      return;
    }
  }
}



public void reverseOrderOfRoster()
{
  Student[] tmp = new Student[studentArray.length];
  for(int i = 0; i < numStudents; i++)
  {
    tmp[i] = studentArray[numStudents - i - 1]; 
  }
  studentArray = tmp;
}