Anyone who is involved in many activities typically uses a calendar to keep track of the various activities. Colleges commonly maintain several calendars such as an academic calendar, a school events calendar, and a sporting events calendar. We have defined an Activities Calendar ADT below that can keep track of one activity per day over a given range of dates. Select a data structure and implement the ADT.
* ActivitiesCalendar( dateFrom, dateTo ): Creates a new empty activities calendar initialized to the given range of dates. The date range can be specified for any non-overlapping period. The only requirements are that dateFrom must precede dateTo and dateTo cannot overlap the day and month of dateFrom for the next year.
* length (): Returns the number of activities on the calendar.
* getActivity( date ): Returns the string that describes the activity for the given date if an activity exists for the given date; otherwise, None is returned.
* addActivity( date, activity ): Adds the given activity description to the calendar for the given date. The date must be within the valid date range for the calendar.
* displayMonth( month ): Displays to standard output all activities for the given month. The display includes the year and name of the month and the list of activities for the month. The display of each activity includes the day of the month on which the activity occurs and the description of the activity.