Saving all Inputs entered for display on cout - C++ - c++

Question

I have looked in the forum but can't seem to find anything specific to what I need.
I am writing a program that asks the user to input a number of students. Depending on the number of students they enter they will then have to enter the students name and a series of 10 grades, or pressing 999 to cancel. The program will later have to display all students entered with their average grade. What I have now just overrides the previous inputs and displays the last one entered.
This is what I have so far:
#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
int main() {
std::string teacherName = "";
std::string classDesignation ="";
int numStudents = 0;
std::string studentName = "";
double grade[10];
double averageGrade = 0.00;
char letterGrade;
std::cout << "Enter the teacher's name: ";
getline(std::cin, teacherName);
std::cout << "Enter the class designation: ";
getline(std::cin, classDesignation);
std::cout << "Enter the number of students ( 1 or more ): ";
std::cin >> numStudents;
std::cin.ignore();
for (int x = 0; x <= numStudents - 1; x++) {
std::cout << "Enter the student's name: ";
getline(std::cin, studentName);
for (int i = 0; i <= 9; i++) {
std::cout << "Enter grade from 0 - 100 or 999 to stop: ";
std::cin >> grade[i];
if (grade[i] == 999){
break;
}
averageGrade += grade[i];
if (averageGrade <= 59){
letterGrade = 'F';
}
if (averageGrade >= 60 || averageGrade <= 69){
letterGrade = 'D';
}
if (averageGrade >= 70 || averageGrade <= 79){
letterGrade = 'C';
}
if (averageGrade >= 80 || averageGrade <= 89){
letterGrade = 'B';
}
if (averageGrade > 90){
letterGrade = 'A';
}
}
}
std::cout << "Teacher: " << teacherName << std::endl;
std::cout << "Class: " << classDesignation << std::endl;
std::cout << "Student Name: " << studentName;
std::cout << std::setw(19) << "Average: " << averageGrade;
std::cout << " Grade: " << letterGrade << std::endl;
std::cout << "Student count: " << numStudents << std::endl;
std::cout << "Student average: " << std::endl;
std::cout << "A's: " << std::endl;
std::cout << "B's: " << std::endl;
std::cout << "C's: " << std::endl;
std::cout << "D's: " << std::endl;
std::cout << "F's: " << std::endl;
return 0;
}
Any tips?
Thank you!

Answer 1

#Hansel, here's what I think will work. We'll change this line to get what we want:
averageGrade += grade[i];
To:
//to declarations:
double averageGradeSum = 0.00;
//then change the line mentioned before to:
averageGradeSum += grade[i];
Then:
//if for some reason you're indexing starts at 1
averageGrade = averageGradeSum/i;
//if indexing starts at 0 like usual C++ use:
averageGrade = averageGradeSum/(i+1);
I'm not going to test this. It should make sense and if I screwed up the syntax it should be an easy google adventure to fix. Enjoy :)

Answer 2

From what I see, you can store them in associative vectors, one for the student name, and one for the average grade. You can also have a doubly linked list of student nodes which would look something like this:
struct student
{
std::string student_name;
int ave_grade;
// Head points to the previous student in the array.
// Tail points to the next student in the array.
student *head;
student *tail;
}
Declare a struct that everything hangs from to prevent memory leaks: student list_head; and each time you have an input, add a new node to the list.