please answer problem 29-30-31 which are all related to each other this class is C++

d. Write a test plan for your class. 29. DateType keeps only the integer representation of the month, day, and year: When a month is wanted in string form, the string is calculated. An alternate approach would be to add a string field to the date and calculate and store the string repre- sentation in the Initialize function. Which methods would have to be changed? Would this change make the use of an if statement to find the appropriate string more or less attractive? Write the code for this ifstatement. 30. What changes would be necessary if the number of days in the month were carried as a data field in class DateType rather than being looked up when necessary? Would this change make the use of a switch statement to find the number of days in the month more attractive? Write the code for this switch statement. 31. Compare and contrast the implementation of class DateType used in the Case Study and the solution proposed in Exercises 29 and 30. These two approaches represent the classic trade-off between space and algorithm complexity. Please comment