Question

C ++ . In professor Maximillian’s course, each student takes four exams. A student’s letter grade is determined by first calculating her weighted average as follows:

                                                (score1 + score2 + score3 + score4 + max_score)
weighted_average = -----------------------------------------------------------------------
                                                                                                5

This counts her maximum score twice as much as each of the other scores. Her letter grade is then a A if weighted average is at least 90, a B if weighted average is at least 80 (but under 90), a C if weighted average is at least 70 (but under 80), a D if weighted average is at least 60 (but under 70), or an F if weighted average is under 60. You should use a nested if-else-if to determine the grade.

You are asked to write a program to get a student’s ID and exam scores, and displays student ID, weighted average and letter grade. The program should keep on running as long as student ID entered is not -1.

Here is a run-time example:

Enter student’s ID: A123

Enter student’s four exam scores, separate each by a space: 56 87 92 86

The weighted average for student A123 is 82.6, letter grade is B.

Enter student ID: -1

Good Bye.

Answer 1

#include <iostream>
#include<string>
using namespace std;

int main()
{
string studentId;
int scores[4];//array to store the scores of the exams
int max_score,total;
float weighted_avg;
char grade;
cout<<"Enter student ID: ";
cin>>studentId;
//loop runs as long as the student ID is not -1
while(studentId.compare("-1")){
cout<<"Enter student’s four exam scores, separate each by a space: ";
for(int i=0;i<4;i++){
cin>>scores[i];
}
max_score=0;
//to calculate the maximum score among four exams
for(int i=0;i<4;i++){
if(scores[i]>max_score){
max_score=scores[i];
}
}
//to calculate total sum of scores plus maximum score
total=max_score;
for(int i=0;i<4;i++){
total=total+scores[i];
}
//to calculate weighted average
weighted_avg=total/5;
//to assign a grade
if(weighted_avg>=90){
grade='A';
}
else if(weighted_avg>=80 && weighted_avg<90){
grade='B';
}
else if(weighted_avg>=70 && weighted_avg<80){
grade='C';
}
else if(weighted_avg>=60 && weighted_avg<70){
grade='D';
}
else if(weighted_avg<60){
grade='F';
}
cout<<"The weighted average for student "<<studentId<<" is "<<weighted_avg<<", letter grade is "<<grade<<"."<<endl;
cout<<"Enter student ID: ";
cin>>studentId;
}
cout<<"Good Bye."<<endl;
return 0;
}

Answer 2

I have implemented the code as required.Please find the code and the screenshot below.

Code:

#include <iostream>

#include <string>

using namespace std;

int main() {

    int num[4];         // array to store all the scores

    string id = "";     // store id

    int max = -1;       // variable to count max_score

    int sum = 0;        // variable to calculate total

    string grade;       // variable to store grades

    float avg;          // variable to store weighted average

    while(true){        // loop infintely

        cout << "Enter student’s ID: ";     

      cin >> id;

        if (id == "-1"){        // if user enters -1 as id, exit from the loop

            break;

        }

        cout << "Enter student’s four exam scores, separate each by a space: ";

        cin >> num[0] >> num[1]>> num[2]>> num[3];

        for (int i = 0;i<4;i++){

            if (num[i]>max){

                max = num[i];       // calculate highest score

            }

            sum += num[i];

        }

        sum += max;

        avg = float(sum)/5;         // get weighted avg

        if (avg>=90){

            grade = 'A';

        }

        else if (avg>=80){

            grade = 'B';

        }

        else if (avg>=70){

            grade = 'C';

        }

        else if (avg>=60){

            grade = 'D';

        }

        else{

            grade = 'F';

        }

    cout << "The weighted average for student "<<id<<" is "<<avg<<" letter grade is "<<grade<<endl;

    }

    cout <<"Good Bye.";

return 0;

}

Screenshot:

32 grade B else if (avg>-70) grade - 'C 34 35 37 else if (avg>-60) grade D 40 else grade - F 43 cout << "The weighted average for student "<<ìd<<" is "<<avg<<" letter grade is ..<<grade<<endl; cout <<"Good Bye."; 45 46 47 48 49 return 0;

Output

https://StudentWeightedScore.sayandip 199309.repl.run clang version 7.0.0-3ubuntu0.18.04.1 (tags/RELEASE_700/final) Enter student's ID: A172 Enter student's four exam scores, separate each by a space: 56 87 92 86 The weighted average for student A172 is 82.6 letter grade is B Enter student' s ID: A173 Enter student's four exam scores, separate each by a space: 59 82 81 86 The weighted average for student A173 is 162.6 letter grade is A Enter student' s ID: -1 Good Bye-D