In lectures, we explored an application involving a massive collection of UFO sightings. The UFOsighting class stored information about a single sighting and provided methods for accessing that information. The UFOlookup class read in the UFO sighting data from a file, constructed an ArrayList of UFOsighting objects, and then provided methods for selectively looking up sightings based on location or date. For this assignment, you will develop similar classes that store and process quiz data.

Consider a course in which quizzes may be administered on any given day, and the number of points in each quiz can vary. Furthermore, suppose the instructor is extremely forgiving and allows students to retake quizzes as many times as they like. For a given day, only the last quiz grade recorded will count. In addition, the lowest quiz grade (i.e., the quiz with lowest percentage) is dropped. Quiz grades for a given student are stored in a file, with each line specifying the quiz date, points earned and possible points for a single quiz. For example:

    2017/03/10 3 5
    2017/03/12 0 8
    2017/03/12 6 8
    2017/03/17 4 12
    2017/03/19 2 4
    2017/03/17 8 12

This data shows that four quizzes were taken, with the quizzes on 3/12 and 3/17 being taken twice (and so the first scores, 0/8 and 4/12, are discarded). The lowest remaining quiz grade is 2/4, so the overall quiz grade for this student would be (3+6+8)/(5+8+12) = 17/25 = 68.0.

In-Class Exercise (may be completed in pairs)

The Quiz class has been provided for you, which stores the basic information about a quiz. You are to make the following additions to the class:

• Add a getPercentage method, which calculates the percentage score for the quiz. The returned value should be rounded to the nearest tenth, so a quiz with 2 out of 3 points would result in a percentage of 66.7.
• Add a toString method, which returns a String representation of the quiz. The returned String should consist of the data, the points earned and possible points, and the quiz percentage, in the following format:

      2017/03/10: earned 3 out of 5 points (60.0%)

Homework Assignment (must be completed individually)

Implement the QuizList class, whose javadoc page is provided. This class will be similar to the UFOlookup class in that it reads and stores data from a file and provides methods for accessing that data. Note the following:

• Constructor: When reading in and storing the individual quiz data, you will need to watch out for repeated quizzes. If a quiz is read in with a date that already has an entry stored, you will need to replace the earlier entry with the new one.
• numQuizzes: This should be very similar to the method in UFOlookup.
• getLowestGrade: This method returns the Quiz object that has the lowest percentage. If there is a tie for the lowest grade, a quiz with the most points should be selected. For example, if there is a tie between 2/4 and 5/10, the 5/10 quiz should be selected as the lowest. If this method is called with no quizzes stored, it should simply return null.
• getPercentage: This method calculates and returns the overall percentage of the quiz grades. As long as there are two or more quizzes recorded, the quiz with the lowest percentage should be dropped and the average of the remaining quizzes returned. Since quizzes may contain different numbers of points, the overall quiz percentage is NOT the average of the individual quiz percentages. Instead, it is the total number of points earned on the quizzes, divided by the total number of points possible. If this method is called with no quizzes stored, it should simply return 0.0.
• showGrades: This method displays all of the quizzes, followed by the overall percentage (rounded to the nearest tenth). For example:

      2017/03/10: earned 3 out of 5 (60.0%)
      2017/03/12: earned 6 out of 8 (75.0%)
      2017/03/17: earned 8 out of 12 (66.7%)
      2017/03/19: earned 2 out of 4 (50.0%)
      overall percentage =  68.0
  

  For extra credit: Ensure that the quizzes are displayed in chronological order, regardless of the order in which the data appears in the file.

Be sure to include javadoc comments in your classes, including your name in the top comment block. Avoid redundancy and be conservative in your use of fields - if a data value does not need to persist over the life of the object, declare it to be local to the method that needs it.