Answered step by step
Verified Expert Solution
Link Copied!

Question

1 Approved Answer

My code is not compiling, cannot figure it out. Need help. C++ This is what is should look like: The computer lab is a system

My code is not compiling, cannot figure it out. Need help. C++

This is what is should look like:

image text in transcribedimage text in transcribedimage text in transcribed

The computer lab is a system that hosts users of several universities computer labs, and allows users of the labs to log into and log off from the available machines. The computer lab system also keeps track of the machines that are available and those that are in use, allowing users to locate an existing computer that is free as well as free the computers (remove users) upon the users logout.

General Specifications for the program

You can run many computer labs. For now, we will have 8 universities under contract. These labs contain computer stations that hold the actual physical work stations that are numbered as shown in the table below:

Lab Number

Computer station numbers

1

1-19

2

1-15

3

1-24

4

1-33

5

1-61

6

1-17

7

1-55

8

1-37

We are going to build each lab as an array. We also will be using a strategy to make these structures which allows them to be different sizes, and this is known as a jagged structure. We will be using a separate array for each universitys computer lab, and those arrays will be different sizes based upon the number of labs required by each university. For example, The University of Akron may have 44 lab stations while Case Western University may have 28, and so on.

Each student or user has a randomly generated unique five-digit ID number. Whenever a user logs on, the users ID (generated by your program), the lab number, the computer station number, name of the student as well as the user login time are inputs into the system. For example, if generated user 49193 logs onto station 2 in lab 3, then your system uses standard input operations and takes the lab number 3, computer station number 2, the name, and the time as the input data. Similarly, when a user logs off a station, then your system takes the lab number and computer station number as inputs.

Your program is used to track, by lab, which user is logged onto which computer, and additionally the program has the capability to maintain those labs computer stations via menu-driven requests. There is an array of lab sizes (one for each lab) that holds the values of the maximum number of possible stations for each given lab, and those sizes are used to build our jagged arrays. These jagged arrays will be dynamically allocated by having another array of pointers allocate and point to array. The jagged array holds the elements (data values) as objects of a lab class. Default values for stations should set to -1 (this indicates it is free or empty)

Support structures

Lets stop for a moment and outline some support structures. We are going to create additional data structures and constants to help out with our programming efforts by reducing the amount of coding that we have to do. We will build an array which holds the values of the maximum number of possible stations for each of the given computer labs (LABSIZES). These represent the sizes of the jagged member arrays. So this array will simply be used to build the 2D jagged arrays. Lets consider this static array to be a control support structure. Here is the code for your program. As you can see, this creates a constant fixed array of length 8 for the labs. Notice NUMLABS is also created to enable us to add or subtract a lab. Using constants here allows our program to be much more dynamic in terms of code modification efforts and control.

// Global Constants

// Number of computer labs

const int NUMLABS = 8;

// Number of computers in each lab

const int LABSIZES[NUMLABS] = {19, 15, 24, 33, 61, 17, 55, 37};

We also have more code for your program. This is another fixed array of information, this array has the name of the university for each lab. They correspond by position with LABSIZES, and so represent a parallel array.

// Names of university of each lab

const std::string UNIVERSITYNAMES[NUMLABS] = {"The University of Michigan", "The University of Pittsburgh", "Stanford University", "Arizona State University", "North Texas State University", "The University of Alabama, Huntsville", "Princeton University", "Duquesne University"};

What happens logically is we can now create iterative code constructs that point to multiple sources of related lab information. So, for example, if we are looping through and stop at the third computer lab, it would represent Stanford University (UNIVERSITYNAMES) which holds 24 work stations (LABSIZES). We will be using this when we access and display arrays in our program.

More Specs

We are going to define a class used to build each lab as an array of objects. The objects will allow us to bundle information, and the array will provide a medium for holding, maintaining, viewing, and arranging this data.

So each user will have a randomly generated unique five-digit ID number, the name of the user, and the time of use too. Whenever a user logs on we input the data into our system. For example, if randomly generated user 49193 Joe Jones logs onto station 2 in lab 3 and uses the computer for 15 minutes, then your system has user ID 49193, Joe Jones, lab number 3, computer station number 2, and time of use 15 as the input data. When a user logs off a station your system uses the lab number and computer station number. The data stored in the array (the object) will be the user ID #, the name, and the amount of time. The lab and station are derived from the arrays structures, not stored.

How it works: we are creating a jagged array. Array #1 holds the pointers (addresses) to each member array. The array of objects, call it Array #2, holds the actual data, the lab user IDs, names, and user times. The array that holds the reference (pointers) for each of the computer stations, the pointers, is used in the dynamic allocation for each of the computer stations, the size of which is determined by the LABSIZES array. So we dynamically allocate the member arrays using the reference array. These are arrays that function as two dimensional. This is a key concept in our projects implementation. The pointer array is static, and placed into local memory in your program. The member array is dynamic, and placed into the heap. If you find your code has references such as **, you did the allocation incorrectly.

Your program should disallow a request for a previously filled slot. When a request to add a new user for an already filled spot occurs, have the program issue the message sorry, that work station is already taken, and return back to the menu for a new request.

Side note so we want the array of objects to be dynamically allocated in memory, i.e., placed on the heap. What if we had used a vector? Is a vector allocated on the stack or the heap? How about the use of the string class within our user written class; will it continue to have the same functionality as a member of this class? Take some time to research these and other questions you might have considered. We will not use a vector, and your research will tell you why

Class Specs

Okay, so the class for the member array contains three elements: the userID, an int, a string containing the users full name, and the time of use which is also an int. Default values for stations should be setting the userID to -1 (this indicates it is free or empty), and the name and time of use to be a blank space and zero respectively. Not that these should be the values you replace when someone requests to logoff. You will want to include a constructor, and may create other constructors that you need to support the creation of objects. Our class has private data, so a user cannot completely initialize an object without the use of a constructor.

You want to define the methods that will support this class. You will definitely want all of the interfaces to go through setters and getters. Consider whether or not you need any operator overloading, such as for outputting (>), assignment (=), and for comparisons (== or > or

Looking at the member arrays, an array of objects, it can be represented as below:

0

1

2

3

4

5

6

etc

User id

Name of student

Time used

User id

Name of student

Time used

User id

Name of student

Time used

User id

Name of student

Time used

User id

Name of student

Time used

User id

Name of student

Time used

User id

Name of student

Time used

For accessing the objects we would use the index to locate any particular element.

Another sample view of the lab array of objects with data is given here, and you can see where user 49193 is logged into station 2 in lab 3, and user 99577 is logged into station 1 of lab 4:

Lab Number

Computer station numbers

1

1: empty 2: empty 3: empty 4: empty 19: empty

2

1: empty 2: empty 3: empty 4: empty 15: empty

3

1: empty 2: 49193, Joe Jones, 60 3: empty 4: empty 24: empty

4

1: 99577, Mary Pearl, 15 2: empty 3: empty 4: empty 33: empty

5

1: empty 2: empty 3: empty 4: empty .. 61: empty

6

1: empty 2: empty 3: empty 4: empty . 17: empty

7

1: 89098, Al Gore, 30 2: 67890, George Bush, 60 3: empty ..... 55: empty

8

1: 12345, Bjarne Stroustrup, 45 2: 67899, Prof Will, 15 3: empty ..37: empty

Lab is Full Specs

We havent addressed the fact that this array of objects may fill up, and run out of places to put our data. The logic for accommodating this will be to check on the capacity of the array during login requests, and issue the message sorry, this lab is full. Please try again later. So your program will have to check the array capacity during each login request. Since all unused slots have a value of -1, we can have a helper function do this during insertion requests. If the array has no capacity then the program does not do any insert logic and takes a different path, issuing the message and returning back to the menu without adding the user.

So, to recap, if user 49193 (randomly generated) requests lab 3, our program will check the capacity for lab 3 before attempting any further add logic. If the lab is not full then the request for the new user continues with the computer station, and so on. If the lab is full, however, then the message is displayed, the screen is paused, and then the program returns back to the main menu for the next request.

Menu Specs

As your program starts, before it displays the menu and starts processing requests, display the universities and their appropriate labs as seem below. Do this only once.

Create a repeating menu that allows the user of the system to login or logoff users and collect the appropriate data. Whenever someone logs in or logs out, the array should be updated. Along with the options to log in and log out, include a display option that offers the user the opportunity to print any one of the four labs on the screen. Also, include a search option so that the administrator can type in a user ID and the system will output what lab and station number that user is logged into, or that user is not logged on if the user ID is not logged into any computer station. Formatting of your menu should match exactly to the example below.

Important do not ask the user if they wish to continue that is the purpose of the menu, and specifically option 5. You should pause the program so the user can view the result (consider cin.get()) and press any key to continue. If your program prompts the user for something like enter Y to repeat then youll lose points L

Input Specs

Create logic to randomly generate an ID for the user. This user ID will continue to be the data type of integer, and will be up to 5 digits in length. The values are 1 99999, and should appear with all 5 digits (leading zeroes) on the display upon generating them. Certainly consider random and seed appropriately. Also, check out the setfill manipulator as a possible helper for this leading zeroes thing. Setfill allows you to set a fill character to a value using an input parameter, such as 0 for leading zeroes. This will allow you to print user ID 34, for example, as 00034. That is what is required. Researching it, youll see that you will need to reset setfill after use too, or you will be printing a lot of zeroes on the display! These are integers do not use strings. Your program also should guarantee an absolutely unique user ID has been generated for each new activity that is added. Think about how this works

When the login request is invoked you will use a randomly generated user ID, and then take input for the name of the user (std::string type) and the time used (integer). Can we verify these? Yes, and we absolutely must do that. Consider what is a valid name? Lets establish the maximum length to be 35 characters long. And lets say valid names should not be blank, either. Write the logic to support all of that. Input of the time used requires it to be either 15, 30, 45, or 60. These are the only valid entries that the system accepts for the time used. Validation may be done using the method you write to take the data, or it can be made into separate helper functions.

Output Specs

Along with the options to log in and log out, include a display option that offers the user the opportunity to print any one of the labs on the screen. Also, include a search option so that the administrator can type in a user ID and the system will output what lab and station number that user is logged into, or that user is not logged on if the user ID is not logged into any computer station. For searches you must show the user id and additionally the user name and time of use. Notice the display of the labs will be displaying the user ID and also the name of the university such as Lab # 2, The University of Pittsburgh

Finally, add a check of the capacity of the array for login requests. When a lab gets full, and issue the accompanying message Lab 2, The University of Pittsburgh, is at full capacity. Please try your request again later.

See the examples below for more regarding output specs.

Again, make use of manipulators such as setw for the output and match the output samples.

Test, test, and test again

Code as minimally as possible. Test thoroughly, and test incrementally.

Whats going on for this release?: 1) create a repeating menu with the 5 options described; 2) youll be making your member arrays as arrays of objects (dynamically allocated arrays of objects); 3) randomly generate user IDs, and include two validated fields from input into the member array; 4) include a parallel array that holds the names of the university of each lab that is displayed at the initial execution of the program; 5) Check lab capacity for login requests, and; 6) match your systems input or output of the data as described.

Here is my code so far, but its not working, needs to fix. Please help:

#include #include #include #include

using std::string; using std::cout; using std::cin;

//Type definition typedef int* IntPtr;

//Global Constants // Number of computer labs const int NUMLABS = 8;

const string NUMUNIVERSITIES="8";

//Function Prototypes void createArrays(IntPtr labs[], int labsizes[]); void freeArrays(IntPtr labs[]); void showLabs(IntPtr labs[],int labsizes); void login(IntPtr labs[], int labsizes[]); void logoff(IntPtr labs[], int labsizes[]); void search(IntPtr labs[], int labsizes[]);

//Create Arrays void createArrays(IntPtr labs[], int labsizes[]) { int i,j; for (i=0; i

} return; }

//Release the allocated memory void freeArrays(IntPtr labs[]) { int i; for(i=0; i

// implement the showLabs method with universities names void showLabs(IntPtr labs[], int labsizes[]) { string UNIVERSITYNAMES[8];

//Initializing names of university of each lab UNIVERSITYNAMES[0] = "The University of Michigan"; UNIVERSITYNAMES[1] = "The University of Pittsburgh"; UNIVERSITYNAMES[2] = "Stanford University"; UNIVERSITYNAMES[3] = "Arizona State University"; UNIVERSITYNAMES[4] = "North Texas State University"; UNIVERSITYNAMES[5] = "The University of Alabama, Huntsville"; UNIVERSITYNAMES[6] = "Princeton University"; UNIVERSITYNAMES[7] = "Duquesne University";

int lab;

std:: cout > lab;

int validateLab(lab); std::cout

for(int i = 0; i

// implement the login method void login(IntPtr labs[], int labsizes[]) { int id = -1,lab =-1,num =-1; while((id99999)) { std::cout >id; } while((labNUMLABS)) { std::cout >lab; } while((numlabsizes[lab-1])) { std::cout >num; }

if(labs[lab-1][num-1] !=-1) { std::cout

labs[lab-1][num-1]=id; return; } // implement the logoff method void logoff(IntPtr labs[], int labsizes[]) { int id=-1, i,j; while ((id99999)) { std::cout>id; } for(i=0; i

} } std::cout99999)) { std::cout>id; } for(i=0; i

} } std::cout

}

//implement the main method int main() { IntPtr labs[NUMLABS]; // Array to referrence each lab int labsizes[NUMLABS]; // Number of computer in each lab int choice=-1;

//Initializing labsizes given in the problem labsizes[0]=19; labsizes[1]=15; labsizes[2]=24; labsizes[3]=33; labsizes[4]=61; labsizes[5]=17; labsizes[6]=55; labsizes[7]=37;

createArrays(labs,labsizes); // Create ragged struture while(choice != 0) { std::cout

std::cout>choice;

if(choice==1) { login(labs, labsizes); } else if(choice==2) { logoff(labs, labsizes); } else if(choice==3) { search(labs, labsizes); } else if(choice==4) { showLabs(labs,labsizes); } else if(choice==5) { freeArrays(labs); }

} // free the allocates memory freeArrays(labs); return 0; }

Student Name Incorporated Computer Lab System MAIN MENU 1) Simulate login 25 simulate logoff 3) Search 4) Display a lab Your choice: 3 Enter the 5 digit ID number of the user to find: 65432 User 65432 is in lab 4 at computer 22 Student Name Incorporated Computer Lab System MAIN MENU 1) Simulate login 25 simulate logoff 3) Search 4) Display a lab Your choice: 3 Enter the 5 digit ID number of the user to find: 65432 User 65432 is in lab 4 at computer 22

Step by Step Solution

There are 3 Steps involved in it

Step: 1

blur-text-image

Get Instant Access to Expert-Tailored Solutions

See step-by-step solutions with expert insights and AI powered tools for academic success

Step: 2

blur-text-image

Step: 3

blur-text-image

Ace Your Homework with AI

Get the answers you need in no time with our AI-driven, step-by-step assistance

Get Started

Recommended Textbook for

Filing And Computer Database Projects

Authors: Jeffrey Stewart

2nd Edition

007822781X, 9780078227813

More Books

Students also viewed these Databases questions

Question

Explain basic guidelines for effective multicultural communication.

Answered: 1 week ago

Question

Identify communication barriers and describe ways to remove them.

Answered: 1 week ago

Question

Explain the communication process.

Answered: 1 week ago