The top-level representation of a queue is a structure of type queue_t. In the starter code, this structure contains only a single field "head", but you will want to add other fields. The queue contents are represented as a singly-linked list, with each element represented by a structure of type list_ele_t that has the fields "value" and "next", storing a queue value and a pointer to the next list element respectively. You may add other fields to this structure, although you should not need to do so. In the starter code, a queue is a pointer of type queue_t *; we distinguish two special cases: a NULL queue is one for which the pointer is set to NULL, an empty queue is one pointing to a valid queue_t structure with a head field set to NULL. You need to properly handle both of these cases, as well as queues containing one or more elements. Your task is to modify the code in queue. h and queue. c to fully implement the following functions: • q_new: create a new, empty queue. • q_free: free all storage usted by a queue. • q_insert_head: attempt to insert a new element at the head of the queue. • q_insert_tail: attempt to insert a new element at the tail of the queue. • q_remove_head: attempt to remove the element at the head of the queue. • q_size: compute the number of elements in the queue. • q_reverse: reorder the list so that the queue elements are reversed in order. The following notes are about how you must implement these functions

Consider the following statements: #include #include class temporary { private: string description; double first; double second; public: temporary(string = "", double = 0.0, double = 0.0); void set(string, double, double); double manipulate(); void get(string& , double& , double& ); void setdescription(string); void setfirst(double); void setsecond(double); }; write the definition of the member function set() so that the instance variables are set according to the parameters. write the definition of the constructor so that it initializes the instance variables using the function set() write the definition of the member function manipulate() that returns a decimal number (double) as follows: if the value of description is "rectangle", it returns first * second if the value of description is "circle" it returns the area of a circle with radius first if the value of description is "cylinder" it returns the volume of a cylinder with radius first and height second. hint: the volume of a cylinder is simply the area of the circle at the base times the height. if the value of description is "sphere" it returns the volume of the sphere with radius first. otherwise it returns -1.0;

Calculating the "total price" of an item is tedious, so implement a get_item_cost method that just returns the quantity times the price for an item. by the way, the technical term for this kind of instance method is an accessor method, but you'll hear developers calling them getters because they always start with "get" and they get some value from instance attributes. in order to make the items sortable by their total total price, we need to customize our class. search the lectures slides for "magic" to see how to do this. see section 9.8 for an additional reference. the receipt class: this will be the class that defines our receipt type. obviously, a receipt will consist of the items on the receipt. this is called the composition design pattern. and it is very powerful. instance attributes: customer_name : it is very important to always know everything you can about your customers for "analytics", so you will keep track of a string customer name in objects of type receipt. date : the legal team has required that you keep track of the dates that purchases happen for "legal reasons", so you will also keep track of the string date in objects of type receipt. cart_items : this will be a list of the items in the cart and hence end up on the receipt. methods: 1. create a default constructor that can take a customer name as an argument, but if it gets no customer name, it will just put "real human" for the customer_name attribute. it should also accept a date argument, but will just use the value "today" for the date instance attribute if no date is given. the parameters should be named the same as the instance attributes to keep things simple. 2. add_item : self-descriptive. takes a parameter which we hope beyond hope is of type itemtopurchase and adds it to the cart_items. returns none. 3. print_receipt : takes a single parameter isevil, with default value true. returns a total cost of all the items on the receipt (remember to factor in the quantity). prints the receipt based on the following specification: for example, if isevil is true, and customer_name and date are the default values: welcome to evilmart, real human today have an evil day! otherwise, it should print: welcome to goodgo, real human today have an good day! then the receipt should be printed in sorted order like we discussed earlier, but whether or not it starts with the highest cost (think reverse), depends on the value of isevil. if it is evil, then the lowest cost items should print first, but if it is good, then it will print the highest cost items first. (cost meaning price*quantity). remember to return the total cost regardless! your main() function: the main flow of control of your program should go in a main() function or the program will fail all the unit tests. get the name of the customer with the prompt: enter customer name: get the date with the prompt: enter today's date then, ask the question: are you evil? your program should consider the following as true: yeah yup let's face it: yes hint: what do these strings all have in common? your program should consider all the following as false: no nah perhaps but i'm leaning no (just be glad you don't have to handle "yeah no.") okay enough horsing around. (get it? aggies? ! horsing! ) next, in the main() function, you will have to create a receipt object and start adding things into it using an input-while loop. the loop will prompt the user for the item name exactly as in the previous zylab (9.11). but unlike the previous zylab, the loop will terminate only if an empty string is entered for the item name. then, the price and the quantity will be prompted for exactly as in the previous zylab. create the itemtopurchase objects in the same manner as the previous zylab, but don't forget to add them to the receipt using your add_item instance method. then, the items on the receipt should be printed with the same formatting as in the previous zylab, of course with either "good" or "evil" ordering. however, on the last line, the total should be printed as follows: where 10 is replaced by the actual total. sample run here is what a sample run of the final program should look like: enter customer name: nate enter today's date: 12/20/2019 are you evil? bwahahahaha yes enter the item name: bottled student tears enter the item price: 2 enter the item quantity: 299 enter the item name: salt enter the item price: 2 enter the item quantity: 1 enter the item name: welcome to evilmart, nate 12/20/2019 have an evil day! salt 1 @ $2 = $2 bottled student tears 299 @ $2 = $598 total: $600

Assume that there is a 4% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on three independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?