Instructions

1. Go to the Modules section on Canvas, find the Midterm 2 Coding link, and click on it to start the exam.
2. Type the answer to the two coding questions in the space provided and nicely format your code using indenting.
3. When you are finished start working on your lab.
4. You may not be able to finish all the problems. If so, please do not worry. We will award partial credit. Your strategy should be to first put down something reasonable for each problem and save your work. Then if you have time, go back and try to flesh out your answer or correct any syntax issues.
5. You have 1 hour to complete the exam. Please do not discuss the exam with anyone from another lab section until after 3:00pm.
6. Remember to pass all object parameters by reference and when they are not being modified, to also declare them as const!
7. Your work must be your own, not anyone else's.
8. Do not show me include statements or a main for either problem. Just show me the function you are requested to write.
9. Good luck!

1. (30 points): Write a void function named updateUser that either creates a new user object and inserts the object in sorted alphabetical order based on the user's name into a list, or, if the user already exists, adds the indicated amount to their balance. insertUser takes three arguements:
   1. userList: an STL list of pointers to User objects.
   2. name: the name of the user
   3. amount: the amount to add to the user's balance. If the user is a new user, then this amount will be the initial balance for the user.

   You are given the following class declaration for User:

   class User {
   public:
     string name;
     double balance;
     User(string n, double amount): name(n), balance(amount) {} 
   };
   

   As an example, suppose that successive calls were made with the following users and amounts:

     charley 20
     nancy 10
     anne 25.5
     anne 15
     zack 75
     nancy 25.15
   

   Then when the final call returned, your list would contain pointers to the following User objects and they would be in this exact order:

     {anne, 40.5}, {charley, 20}, {nancy, 35.15}, {zack, 75}
   

2. (30 points): Write a C++ method named InsertReservation to add a new reservation to a hotel's reservation system if the room is not occupied for those dates. Each room will have a map showing the dates it is occupied and the guest in the room on each date. A hotel will have a map with a pair for each room number and the room's occupancy map.

   The function will take four parameters: the guest name, the room number, the check in date, and the check out date. For simplicity dates will be simple integers starting at one and the guest will not be considered to be staying in the room on the check out date. For example, suppose you get the following calls to InsertReservation:

         InsertReservation("rabbit", 2, 10, 12)
         InsertReservation("hound", 2, 1, 6)
         InsertReservation("hen", 2, 7, 11)
         InsertReservation("chicken", 2, 1, 20)
       

   The reservations will be processed as follows:
   1. rabbit is inserted into the map associated with room 2 with the two pairs (10, "rabbit") and (11, "rabbit") to denote the two days rabbit is staying in room 2.
   2. hound is inserted into the map associated with room 2 with the pairs (1, "hound"), (2, "hound"), ..., (5, "hound") to denote the five days hound will be staying in room 2.
   3. hare's reservation is rejected because hare's occupancy dates overlap with a pre-existing reservation for rabbit.
   4. chicken's reservation is rejected because chicken's occupancy date overlaps with a pre-existing reservation for hound.

   When these 4 calls are complete, the map associated with room 2 will have the following key/value pairs:

         (1, "hound"), (2, "hound"), (3, "hound"), (4, "hound"),
         (5, "hound"), (10, "rabbit"), (11, "rabbit")
         

   You are given the following class definition for a Hotel:

   class Hotel {
   public:
     void CreateRoom(int r);  // adds the room to reservations with an empty map
     void InsertReservation(string guest, int room,
   			 int checkInDate, int checkOutDate);
   protected:
     map<int, map<int, string> * > reservations;
   };
   

   The key for the reservations map is a room number and the value is a pointer to a map<int, string> that holds day/guest name pairs where day is a day the room is occupied and guestname is the name of the guest occupying the room on that day. There will be one entry in the map for each day that the guest is staying in the room, as illustrated in the above example.

   Your function must perform the following tasks:

   1. If the room does not exist, then throw the string "no such room".
   2. If the room is occupied during the requested days of the reservation, then throw the string "room occupied". You can use the map function lower_bound(key) to return an iterator that points to the first date equal to or greater than the check in date. For example, hound's requested check-in date is 1 and lower_bound will return an iterator that points to day 10. As another example, hare's requested check-in date is 7 and lower_bound will again return an iterator that points to day 10. If there is no entry equal to or greater than the date, then lower_bound returns an iterator to .end(). For example, when you try to insert rabbit in the above example, lower_bound will return .end() because there is no entry in the room 2 map that is equal to or greater than 6. You should be able to figure out how to use this returned date (e.g., 10) to determine whether or not the room is occupied during the requested dates.
   3. If the reservation is valid, then insert the guest into the room's map for the specified days (remember to not include the check out day).