Question

I want to change this code and need help. I want the code to not use parallel arrays, but instead use one array of struct containing the data elements, String for first name, String for last name,Array of integers for five (5) test scores, Character for grade. If you have any idea help would be great.

#include
#include
#include
#include

using namespace std;

const int NUMBER_OF_ROWS = 10; //number of students
const int NUMBER_OF_COLUMNS = 5; //number of scores

void readData(ifstream&, string[], int, int[][NUMBER_OF_COLUMNS]);
void calculateAverages(const int[][NUMBER_OF_COLUMNS], int, char[], double&);
void printResults(string names[NUMBER_OF_ROWS], int scores[NUMBER_OF_ROWS][NUMBER_OF_COLUMNS],
   char grade[NUMBER_OF_ROWS], double avgScore);

int main()
{

   ifstream infile;
   infile.open("Data.txt");
  
   string names[NUMBER_OF_ROWS]; //students names
   char grades[NUMBER_OF_ROWS]; //grades
   int scores[NUMBER_OF_ROWS][NUMBER_OF_COLUMNS]; //test scores

   double avgScore; //overall class Average

   if (!infile) {
       cout << "Cannot open input file. Program terminated!" << endl;
       return 1; //end program with error
   }
  
   readData(infile, names, NUMBER_OF_ROWS, scores);
  
   calculateAverages(scores, NUMBER_OF_ROWS, grades, avgScore);

   printResults(names, scores, grades, avgScore);
   cout << endl;

   infile.close();//close input file

   return 0;
}

void readData(ifstream& infile, string names[], int length, int scores[][NUMBER_OF_COLUMNS]) {
   for (int index = 0; index < length; index++) {
       infile >> names[index]; //name stored in 1-dim string array
  
       for (int ts = 0; ts < NUMBER_OF_COLUMNS; ts++) {
           infile >> scores[index][ts];
       }

   }
}

void calculateAverages(const int scores[][NUMBER_OF_COLUMNS], int length, char grades[], double& avgScore) {
   int totalStudentScore = 0;
   int totalClassScore = 0;

   for (int index = 0; index < length; index++) {
       totalStudentScore = 0;
       for (int s = 0; s < NUMBER_OF_COLUMNS; s++) {
           totalStudentScore += scores[index][s];
       }

       //grade ranges: A(90-100), B(80-89), C(70-79), D(60-69), F(<60)
       int studentAvg = (totalStudentScore / NUMBER_OF_COLUMNS);
       if (studentAvg >= 90) {
           grades[index] = 'A';
       }
       else if (studentAvg >= 80 && studentAvg < 90) {
           grades[index] = 'B';
       }
       else if (studentAvg >= 70 && studentAvg < 80) {
           grades[index] = 'C';
       }
       else if (studentAvg >= 60 && studentAvg < 70) {
           grades[index] = 'D';
       }
       else {
           grades[index] = 'F';
       }
       totalClassScore += totalStudentScore; //add to total class score
   }

   avgScore = static_cast (totalClassScore) / (length * NUMBER_OF_COLUMNS); //avg score range 0-100

}

void printResults(string names[NUMBER_OF_ROWS], int scores[NUMBER_OF_ROWS][NUMBER_OF_COLUMNS],
   char grade[NUMBER_OF_ROWS], double avgScore)
{

   cout << fixed << showpoint << setprecision(2);
   cout << setw(10) << left << "Name" << setw(9);
   cout.setf(ios::right);
   cout << "Test1" << setw(8) << "Test2" << setw(9) << "Test 3" << setw(8) << "Test 4" << setw(7)
       << "Test5" << setw(19) << "Average Score" << setw(8) << "Grade" << endl;

cout << "-------------------------------------------------------------------------------" << endl;

   for (int i = 0; i < NUMBER_OF_COLUMNS; i++)
   {
       cout.unsetf(ios::right);
       cout.setf(ios::left);
       cout << setw(7) << names[i] << setw(9);
       cout.unsetf(ios::left);
       cout.setf(ios::right);
       cout << fixed << showpoint << setprecision(2);
       for (int index = 0; index < NUMBER_OF_COLUMNS + 1; index++)
       {
           if (index == NUMBER_OF_COLUMNS)
           {
               cout << setw(11) << scores[i][index];
               cout << setw(15) << grade[i] << endl;
           }
           else
           {
               cout << scores[i][index] << setw(8);
           }
       }
   }
   cout << endl << "The Average for the Class is: " << avgScore << endl;

}

Here is Data.txt

Jack Ray 85 83 77 91 76
Nate Johnson 80 90 95 93 48
Sam Tylor 78 81 11 90 73
Zach Bell 92 83 30 69 87
Billy Bob 23 45 96 38 59
Alex Great 60 85 45 39 67
Toby Keith 77 31 52 74 83
Mark Alan 93 94 89 77 97
Faith Peep 79 85 28 93 82
Randy Willison 85 72 49 75 63

Answer 1

Below are the screenshots of modified code and output:

I modified your code so as to use a struct array of student instead of using multiple arrays to store names,scores,grades and averages. The student struct has members firstname,lastname,grade,scores & avgScore. Below is the modified code:

 #include<bits/stdc++.h> using namespace std; const int NUMBER_OF_STUDENTS = 10; //number of students const int NUMBER_OF_SCORES = 5; //number of scores //creating struct student struct student{ string firstname;//students first names string lastname;//students last names char grade; //grades int scores[NUMBER_OF_SCORES]; //test scores double avgScore;//avg score }; //modified prototype declaration void readData(ifstream&, student[], int); void calculateAverages(student[], int,double& ); void printResults(student[], double avgScore); int main() { ifstream infile; infile.open("Data.txt"); //struct array declaration student students[NUMBER_OF_STUDENTS]; double avgScore; //overall class Average if (!infile) { cout << "Cannot open input file. Program terminated!" << endl; return 1; //end program with error } //modified function calls readData(infile, students, NUMBER_OF_STUDENTS); calculateAverages(students, NUMBER_OF_STUDENTS,avgScore); printResults(students, avgScore); cout << endl; infile.close();//close input file return 0; } //modified function definition void readData(ifstream& infile, student students[], int length) { for (int index = 0; index < length; index++) { infile >> students[index].firstname >> students[index].lastname; //name stored in student array's firstname and lastname attribute for (int ts = 0; ts < NUMBER_OF_SCORES; ts++) { infile >> students[index].scores[ts];//scores stored in student array's scores[] attribute } } } //modified function definition void calculateAverages(student students[], int length ,double& avgScore) { int totalStudentScore = 0; int totalClassScore = 0; for (int index = 0; index < length; index++) { totalStudentScore = 0; for (int s = 0; s < NUMBER_OF_SCORES; s++) { totalStudentScore += students[index].scores[s]; } //grade ranges: A(90-100), B(80-89), C(70-79), D(60-69), F(<60) students[index].avgScore = (totalStudentScore / NUMBER_OF_SCORES); if (students[index].avgScore >= 90) { students[index].grade = 'A'; } else if (students[index].avgScore >= 80 && students[index].avgScore < 90) { students[index].grade = 'B'; } else if (students[index].avgScore >= 70 && students[index].avgScore < 80) { students[index].grade = 'C'; } else if (students[index].avgScore >= 60 && students[index].avgScore < 70) { students[index].grade = 'D'; } else { students[index].grade = 'F'; } totalClassScore += totalStudentScore; //add to total class score } avgScore = (totalClassScore)/(length * NUMBER_OF_SCORES); //avg score range 0-100 } //modified function definition void printResults(student students[], double avgScore) { cout << fixed << showpoint << setprecision(2); cout << setw(10) << left << "Name" << setw(9); cout.setf(ios::right); cout << "Test1" << setw(8) << "Test2" << setw(9) << "Test 3" << setw(8) << "Test 4" << setw(7) << "Test5" << setw(19) << "Average Score" << setw(8) << "Grade" << endl; cout << "-------------------------------------------------------------------------------" << endl; for (int i = 0; i < NUMBER_OF_STUDENTS; i++) { cout.unsetf(ios::right); cout.setf(ios::left); cout << setw(16) << students[i].firstname+" "+students[i].lastname; cout.unsetf(ios::left); cout.setf(ios::right); cout << fixed << showpoint << setprecision(2); for (int index = 0; index < NUMBER_OF_SCORES + 1; index++) { if (index == NUMBER_OF_SCORES) { cout << setw(15) << students[i].avgScore; cout << setw(11) << students[i].grade << endl; } else { cout << students[i].scores[index] << setw(8); } } } cout << endl << "The Average for the Class is: " << avgScore << endl; }