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C++ Programming: Vectors and Sorting Assignment Instructions

Overview

This assignment utilizes a class in an application that might be useful in the “real world.” It requires the sorting of, and computation with, data stored in a vector inside of a class. In this assignment, you will design an Object-Oriented program and manipulate data using a vector within the class.

Instructions

You are working for a university to maintain a list of grades and some related statistics for a student.

Class and Data members:

Create a class called Student that stores a student’s grades (integers) in a vector (do not use an array). The class should have data members that store a student’s name and course for which the grades are earned.

Constructor(s):

The class should have a 2-argument constructor that receives the student’s name and course as parameters and sets the appropriate data members to these values.

Member Functions:

The class should have functions as follows:

1. Member functions to set and get the student’s name and course variables.

3. A member function to sort the vector in ascending order.

Feel free to use the sort function that is available in the algorithm library for sorting vectors. Here is a web page that may help:

https://www.tutorialspoint.com/sorting-a-vector-in-cplusplus

Or, if you would prefer to write your own sort code, you may find this site to be helpful:

http://www.cplusplus.com/articles/NhA0RXSz/

4. A member function to compute the average (x̄) of the grades in the vector. The formula for calculating an average is

x̄ = ∑xi / n

where xi is the value of each grade and

n is the total number of grades in the vector.

When using a vector, you can manipulate it just like an array. For a review on how to loop over an array to calculate a sum, you may find this video to be helpful:

5. A member function to determine the lowest grade in the vector and a separate member function to determine the highest grade in the vector. [Note that to receive credit for these functions, they must contain an algorithm to search through the vector to determine the minimum or maximum value. You cannot simply sort the vector and return the first or last data member or use the *min_element or *max_element functions.]

Hint: The following web page provides an excellent example of algorithms to find the min and max values in an array: [Look at Technique 2]

https://www.studymite.com/cpp/examples/finding-maximum-and-minimum-number-in-array-in-cpp/

6. A member function (e.g. getNumGrades) to return the number of grades that are stored in the vector. Remember that a vector knows its own size. Therefore, you don’t need to keep track of the number of items stored in a vector in a separate data member in the class. You also don’t want to make your vector public – it should be private. Therefore, you can create a public getNumGrades function that will simply return the size of the vector.

7. A member function to display the student’s name, course, and vector of sorted grades.

Write a program (client) that uses the class by creating a Student object and prompting the user for a file name . Appropriate error checking is required to ensure that the file exists and can be opened successfully. Also, the name of the file may contain a space ; therefore, be sure to use getline instead of cin when you prompt the user to enter the name of the file.

The client should read in the file contents and store them in the object. The file will be formatted such that the first line contains the student’s name, the second line contains the course name, and each successive line contains a grade. A typical input file might contain:

John Smith

CSIS 112

90

85

97

91

87

86

88

82

83

Note that the file may contain any number of grades for a given course. Therefore, you need to read in and store each grade until you reach the end of the file.

Main() should then produce a report that displays the student’s name and course, the total number of grades in the file, the lowest grade, the highest grade, the average of all the grades, and finally, a listing of all of the grades that were read in. The listing of all of the grades must be displayed in sorted order (ascending – from lowest to highest).

All output should be labeled appropriately, and validity checking should be done on input of the filename and also the grades that are read in.

If a non-numeric or negative value is encountered in the file when reading in the grades, the program should output an error message indicating that a non-numeric or negative value was found in the file, and the entire program should then terminate. If a non-numeric or negative value is found, consider the entire file to be corrupted and don’t try to produce any calculations nor display the contents of the vector – just end the program with an appropriate error message. [Make sure the error message is displayed long enough for the user to read it before ending the program. – you may use the system(“pause”) command for this. Note that there are several security and performance issues with using system commands, and you’ll learn more about these later, but for now, feel free to use the system(“pause”) command. ]

The executing program should look something like this:

In the screen above, notice that the average of the grades is displayed with decimal points. Whenever you are calculating a statistic like an average, never truncate the decimal portion unless you are told to do so. Imagine if the average of your grades in this class is 89.9… You definitely do not want your final grade truncated to 89. Therefore, in this assignment, do not truncate the decimal portion of the average you calculate. Remember the rules of integer division. That is, an int divided by an int is an int. Therefore, make sure to convert the numerator or denominator to a double before performing the division.

If a negative grade is read in, the program should look something like this:

If a non-numeric grade is read in, the program should look something like this:

In the screens above, notice that the program pauses long enough to read the error message and no statistics nor grades are displayed. This is accomplished through the use of the system(“pause”) command.

Files were covered in your introduction to C++ programming class. However, you may not have had much experience manipulating them. To assist you in the file aspects of this program, you can view these short videos:

Working with Files

Tips for File Handling

Writing Custom File Structures