Question

C++

Write a program that reads the number of students in the class, then reads each student's name and his/her test score.

Print out each student name, test score and grade, and the average score of the whole class.

The program must use vectors and loops for the implementation.

The grades are determined as follows: A >= 90; 80 <= B < 90; 70 <= C < 80; 60 <= D < 70; F < 60.

Answer 1

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


 const int MAX = 50;
 // a function called GetData to read and store data into two arrays,
 void GetData(ifstream& infile,string name[],int scores[][5],int& n)
 {
    n = 0;
    int i=0;
    int j=0;
    while(!infile.eof())
    {
    infile >> name[i];
    for(int j=0; j<5; j++)
    infile >> scores[i][j];
    i++;
    }
    n = i;
 }

 char determineGrade(double avg)
 {
 if(avg>=90 && avg<=100)
 return 'A';
 else if(avg>=80 && avg<=89)
 return 'B';
 if(avg>=70 && avg<=79)
 return 'C';
 if(avg>=60 && avg<=69)
 return 'D';
 if(avg>=50 && avg<=59)
 return 'F';
 }

 // a function called Average that is used to calculate the average test score and grade,
 void Average(int a[][5],char grade[],double avg[],int no_of_students)
 {
    for(int i=0; i<no_of_students; i++)
    {
    double sum =0;
        for(int j=0; j<5; j++)
        sum+= a[i][j];
    avg[i] = sum/static_cast<double> (5);
    grade[i] = determineGrade(avg[i]);
    }
 }

 // function called PrintResults to output the results.
 void PrintResults(string name[],double avg[],int scores[][5],char grade[],int n)
 {
 for(int i=0; i<n; i++){
 cout << left << setw(10)<< name[i];
    for(int k=0; k<5; k++)
        cout << right << setw(8) << scores[i][k];
    cout << endl;
 }
 cout << setw(8) <<"Average ";
 for(int i=0; i<n; i++)
     cout << setw(5) << avg[i];
     cout << endl;
 }

 int main()
 {
 // a one-dimensional array to store the students� names,
 string name[MAX];
 // a (parallel) two-dimensional array to store the test scores,
 int scores[MAX][5];
 // a parallel one-dimensional array to store grades.
 char grade[MAX];
 int no_of_students;
 double avg[MAX];

 ifstream infile("StudentData.txt");

 if(!infile)
 {
    cout <<"unable to open file.so exiting from program" << endl;
    return 0;
 }

 GetData(infile, name, scores, no_of_students);
 infile.close();
 Average(scores, grade, avg, no_of_students);
 PrintResults(name,avg,scores,grade,no_of_students);


 return 0;
 }