Question

Write a C++ program that asks user number of students in a class and their names. Number of students are limited to 100 maximum. Then, it will ask for 3 test scores of each student. The program will calculate the average of test scores for each student and display with their names. Then, it will sort the averages in descending order and display the sorted list with students’ names and ranking.

Follow the Steps Below

1. Save the project as A4_StudentRanking_yourname.
2. Use functions to divide your program into manageable pieces. Define three functions: displayList, findAverage, and sort.
   1. Write function prototypes at the top and define the functions after the main function.
3. findAverage function:
   1. This function will get 4 parameters: array of student names, 2D array of grades from 3 tests of each student, array of averages to fill in, number of students as the arrays size.
   2. You need nested for loop to calculate average of 3 test scores for each student and record it to the array of averages. (You may define array of names and 2D array of grades as constants in the parameter list since you don’t need to make any changes.)
   3. No return value needed; changes will apply on the original array of averages.
4. displayList function:
   1. This function has 3 parameters: array of student names, array average scores, and the size of the arrays.
   2. The function doesn’t make any changes on the arrays, so define them as constants in the parameter list.
   3. Call the function twice in your program
      1. When averages are calculated
      2. When averages are sorted
5. sort function:
   1. This function gets 3 parameters: array of students, array of averages, and number of students as the size of the arrays.
   2. Use selection sort algorithm. Sort both arrays based on the average scores in descending order. (You will apply the sort on the array of averages by comparing the scores, but apply the swapping on both arrays. They are parallel arrays. This means they use the same index numbers.)
6. Define constants as global constants. Do not use any literal in the program, use their identifiers.
7. Write function prototypes.
8. Keep variable definitions local.
9. At the beginning of the program inform user about the program. Display a message stating that they can enter 3 test scores and any number of students limited to 100.
10. Ask for number of the students to user.
11. Array of students, test scores, and averages are parallel arrays. This means they store related data in the same subscript.
12. The array of test scores is a two-dimensional array. First subscript holds number of students and second subscript holds number of test scores.
13. Validate user input with a while or do-while loop. They shouldn’t exceed the maximum number; also, it can’t be less than 1.
14. Ask for the student names and their test scores. Use getline function to get the students’ full names. You must use cin.ignore() before using the getline function since you also use cin object.
15. Call findAverage function.
16. Call displayList function.
17. Call sort function.
18. Call displayList function.
19. Use comment lines to describe block of code statements in the program.

Answer 1

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#include<bits/stdc++.h>
using namespace std;
void findAverage(string names[],int grades[][3],double averages[],int n)
{
    for(int i=0;i<n;i++)
    {
        int sum=0;
        for(int j=0;j<3;j++)
        {
            sum+=grades[i][j];
        }
        averages[i]=sum/3.0;
    }
}
void displayList(const string names[],const double averages[],const int n)
{
    for(int i=0;i<n;i++)
    {
        cout<<names[i]<<"  "<<averages[i]<<endl;
    }
}
void sortAverages(string names[],double averages[],int n)
{
    // sorting using selection sort
    int i, j, min_idx;
    for (i = 0; i < n-1; i++)
    {
        min_idx = i;
        for (j = i+1; j < n; j++)
        if (averages[j] < averages[min_idx])
            min_idx = j;
        swap(averages[min_idx], averages[i]);
        swap(names[min_idx],names[i]);// swapping names parallely with averages
    }
}
int main()
{
    int n;
    // Input size of the class or number of total students
    cout<<"Enter the number of students between 1 and 100:\n";
    cin>>n;
    int grades[n][3];// this 2d array will hold grades of each student
    double averages[n];// This array will contain the average of the marks
    string names[n];// This will contain the names  of the students
    cout<<"Enter the name and 3 test scores for each of the student:\n";
    for(int i=0;i<n;i++)
    {
        cout<<"Enter the name of the student:\n";
        cin>>names[i];
        cout<<"Enter the marks of "<<names[i]<<":\n";
        for(int j=0;j<3;j++)
        {
            cin>>grades[i][j];
        }
    }
    // calling find average function
    findAverage(names,grades,averages,n);
    cout<<"Student's name with their averages before sorting are:\n";
    displayList(names,averages,n);// This will print average and names before sorting
    sortAverages(names,averages,n);
    cout<<"Student's name with their averages after sorting are:\n";
    displayList(names,averages,n);// This will print after sorting of averages
    return 0;
}

SCREENSHOTS:

#include<bits/stdc++.h> using namespace std; void findAverage (string names[], int grades[] [3], double averages[], int n) AC for(int i=0;i<n;i++) { int sum=0; for(int j=0; j<3; j++) { sum+grades[i] [3]; } averages [i]=sum/3.0; } } void displayList (const string names[],const double averages[],const int n) LUE for(int i=0;i<n;i++) { cout<<names[i]<<" } "<<averages[i]<<endl;

void sortAverages (string names[], double averages[], int n) // sorting using selection sort int i, j, min_idx; for (i = 0; i < n-1; i++) { min_idx = i; for (j = i+1; j<n; j++) if (averages [j] < averages [min_idx]) min_idx = 1; swap (averages [min_idx), averages[i]); swap (names[min_idx], names[i]);// swapping names Ramate with averages } int main() { int n; // Input size of the class or number of total students cout<<"Enter the number of students between 1 and 100:\n"; cin>>n; int grades [n] [3]; // this Pin array will hold grades of each student double averages [n];// This array will contain the average of the marks string names [n];// This will contain the names of the students

cout<<"Enter the name and 3 test scores for each of the student:\n"; for(int i=0;i<n;i++) { cout<<"Enter the name of the student:\n"; cin>>names[i]; cout<<"Enter the marks of "<<names[i]<<":\n"; for(int j=0; j<3;j++) { cin>>grades[i][j]; } } // calling find average function findAverage (names, grades, averages, n) ; cout<<"Student's name with their averages before sorting are:\n"; displayList (names, averages, n);// This will print average and names before sorting sortAverages (names, averages, n) ; cout<<"Student's name with their averages after sorting are:\n"; displayList (names, averages, n);// This will print after sorting of averages return 0;

Enter the number of students between 1 and 100: 4 Enter the name and 3 test scores for each of the student: Enter the name of the student: Harshit Enter the marks of Harshit: 110 20 30 Enter the name of the student: Anmol Enter the marks of Anmol: 20 30 40 Enter the name of the student: Akshat Enter the marks of Akshat: 30 110 50 Enter the name of the student: Shubham Enter the marks of Shubham: 20 40 110 Student's name with their averages before sorting are: Harshit 20 Anmol 30 Akshat 30 Shubham 23.3333 Student's name with their averages after sorting are: Harshit 20 Shubham 23.3333 Akshat 30 Anmol 30 execution time : 53.196 s Process returned 0 (Øx > Press any key to continue.