(EnhancedGradeBook) Modify the GradeBook class of Fig. 19 so that the constructor accepts...

(EnhancedGradeBook) Modify the GradeBook class of Fig. 19 so that the constructor accepts as parameters the number of students and the number of exams, then builds an appropriately sized two-dimensional array, rather than receiving a preinitialized two-dimensional array as it does now. Set each element of the new two-dimensional array to -1 to indicate that no grade has been entered for that element. Add a setGrade method that sets one grade for a particular student on a particular exam. Modify class GradeBookTest of Fig. 20 to input the number of students and number of exams for the GradeBook and to allow the instructor to enter one grade at a time.

Fig. 19 GradeBook class using a two-dimensional array to store grades.

Fig. 20 GradeBookTest creates GradeBook object using a two-dimensional array of grades, then invokes method processGrades to analyze them