Answer to Question #307751 in C++ for yormi

Question

Write a c++ program using two dimensional array that will store the student id number, average quiz score, midterm exam score, and final exam score maximum of 25 students(score must from 0 to) and Instead of forcing the user to enter all of the data at once and displaying all of it, the program will provide menu options that allows user to add new records, delete, update and view all records. It should also provide an option called settings that allows the user to set the grading criteria that will be used in the computation of grades. You may include an additional functionality that allows the user to search a specific record of a student given the student number. A sample menu driven application is given below

Mini Grading System

1. Add New Record

2. Edit Record

3. Delete Record

4. View All

5. Settings

6. Search

7. Exit

Enter your choice:

Answer 1

#include <iostream>
#include <istream>
#include <stdio.h>
#include <conio.h>
#include <string>
#include <fstream>
void login();
void main_menu();
void gpa(float *, char *, float, float, float, float, float);
void create_record();
void display_record();
void display_specific();
void modify_record();
void change_pass();
void delete_record();
using namespace std;
char grade;
float cp_marks, calculus_marks, english_marks, ict_marks, physics_marks ;
float  cgpa, percentage;
float totalmarks = 500;
int n;
struct birthday
{
	int day;
	int month;
	int year;
};
struct student
{
	char name[50], Class[40]; // cstring , character array used //
	char grade;
	birthday b;
	int enroll;
	float cgpa;
} s, *ptr = &s;
int main()
{
	
	system("color 3f");
	login();
	_getch();
}
void main_menu()
{
	int op;
	char x;
	do
	{
		cout << " \n \n \n ";
		cout << " \t \t ";
		cout << " ----------------------------------------------------------" << endl;
		cout << " \t \t ";
		cout << "\t   STUDENT RECORD SYSTEM WITH GPA CALCULATOR " << endl;
		cout << " \t \t ";
		cout << " ----------------------------------------------------------" << endl;
		cout << "\n \t Enter your choice  \n";
		cout << "\t 1 for gpa calculation \n";
		cout << "\t 2 for creating student record \n";
		cout << "\t 3 for displaying overall record \n";
		cout << "\t 4 for displaying specific record \n";
		cout << "\t 5 for modifying the record \n";
		cout << "\t 6 for changing the username & password \n";
		cout << "\t 7 for deleting the record \n";
		cout << " \t ";
		cin >> op;
		switch (op)
		{
		case 1:
			fflush(stdin);
			cout << "\n Enter the marks in Computer out of 100 :  ";
			cin >> cp_marks;
			cout << " \n Enter the marks in Calculus out of 100 :  ";
			cin >> calculus_marks;
			cout << "\n Enter the marks in English out of 100 :  ";
			cin >> english_marks;
			cout << "\n Enter the marks in ICT out of 100 :  ";
			cin >> ict_marks;
			cout << "\n Enter the marks in Physics out of 100 :  ";
			cin >> physics_marks;
			fflush(stdin);
			gpa(&cgpa, &grade, cp_marks, calculus_marks, english_marks, ict_marks, physics_marks);
			cout << "\n cgpa : " << cgpa;
			cout << "\n grade : " << grade;
			break;
		case 2:
			create_record();
			break;
		case 3:
			display_record();
			break;
		case 4:
			display_specific();
			break;
		case 5:
			modify_record();
			break;
		case 6:
			change_pass();
			break;
		case 7:
			delete_record();
			break;
		default: cout << "\n Invalid choice \n";
		}
		cout << "\n do you want to continue ? \n \n";
		cout << " Press y or Y for yes & n or N for No \n";
		cin >> x;
		if (x == 'y' || x == 'Y')
		{
			system("cls");
		}
		else if (x == 'n' || x == 'N')
		{
			exit(0);
		}
	} while (x == 'y' || x == 'Y');
}
void gpa(float *ptr, char *pt, float a, float b, float c, float d, float e)
{
	float totalmarks = 500, cgpa;
	char grade;
	float percentage;
	percentage = (a + b + c + d + e) / totalmarks;
	*ptr = percentage * 4;

	if (*ptr >= 3.5)
	{
		*pt = 'A';

	}
	else if (*ptr >= 3 && *ptr < 3.5)
	{
		*pt = 'B+';
	}
	else if (*ptr >= 2.5 && *ptr < 3)
	{
		*pt = 'B';

	}
	else if (*ptr >= 2 && *ptr < 2.5)
	{
		*pt = 'C';

	}
	else if (*ptr >= 1.5 && *ptr < 2)
	{
		*pt = 'D';

	}
	else
	{
		*pt = 'F';
	}

}

void login()
{
	string username, uname;
	int pass, pass1;
	char x = 'y';
	while (x == 'y' || x == 'Y')
	{
		cout << "\n Username : ";
		cin >> username;
		cout << "\n Password : ";
		cin >> pass;
		ifstream read;
		read.open("user_name.txt");
		getline(read, uname);
		read.close();
		ifstream password;
		password.open("pass.txt");
		password >> pass1;
		password.close();
		if (username == uname && pass == pass1)
		{
			system("cls");
			main_menu();
		}
		else {

			cout << " \n Inavlid login \n";
			cout << " do you want to continue ? \n";
			cout << " press Y or y for yes & n or N for No : \n";
			cin >> x;

		}
		if (x == 'y' || x == 'Y')
		{
			system("cls");
		}
		else
		{
			exit(0);
		}

	}
}

void create_record()
{
	
	cout << "\n for how many students you want to create a record ? \n";
	cin >> n;
	for (int i = 1; i <= n; i++)
	{
		fflush(stdin);
		cout << "\n Enter the name of student  : ";
		cin.get(s.name, 50);
		fflush(stdin);
		cout << " \n Enter the class & section  : ";
		cin.get(s.Class, 40);
		fflush(stdin);
		cout << "\n Enter the enrollment of the student  : ";
		cin >> ptr->enroll;
		fflush(stdin);
		cout << "\n Enter date of birth : ";
		cin >> ptr->b.day >> s.b.month >> ptr->b.year;
		fflush(stdin);
		cout << "\n Enter the cgpa :  ";
		cin >> ptr->cgpa;
		fflush(stdin);
		cout << "\n Enter the grade : ";
		cin >> ptr->grade;
		cout << endl;
		ofstream write;
		write.open("student_record.txt", ios::app);
		write << "\n Name of the student : " << s.name << endl;
		write << " Class of the student : " << s.Class << endl;
		write << " Enrollment of the student : " << ptr->enroll << endl;
		write << " Date of Birth of the student : " << ptr->b.day << "/" << s.b.month << "/" << s.b.year << endl;
		write << " CGPA of student : " << ptr->cgpa << endl;
		write << " Grade of student : " << ptr->grade << endl << endl;
		write.close();
	}
}

void display_record()
{
	string name;

	ifstream read;
	read.open("student_record.txt");
	if (read.is_open())
	{
		while (!read.eof())
		{
			getline(read, name);
			cout << name << endl;
		}
		read.close();
	}
	else
		cout << "\n Unable to open file " << endl;

}

void delete_record()
{
	ofstream del;
	string s = "";
	del.open("student_record.txt");
	if (del.is_open())
	{
		del << s;
		cout << "\n Record deleted \n";
	}
	else
		cout << "\n Unable to open the file \n";
}

void modify_record()
{
int id;
	cout << "\n Enter the id you want to modify : ";
	cin >> id;
	if (id == s.enroll)
	{
		cout << " \n id found : \n";
		cout << " Name of the student : ";
		cin >> s.name;
		cout << "\n Class of the student : "; 
		cin >> s.Class;
		cout << "\n Enrollment of the student : "; 
		cin >> ptr->enroll;
		cout << "\n Date of Birth of the student : ";
		cin >> ptr->b.day >> s.b.month >> s.b.year ;
		cout << "\n CGPA of student : ";
		cin >> ptr->cgpa;
		cout << " Grade of student : "; 
		cin >> ptr->grade; 
	}
}


void change_pass()
{
	string username, uname;
	int pass, pass1;
	cout << "\n Enter the current username : ";
	cin >> username;
	cout << "\n Enter current password : ";
	cin >> pass;
	ifstream read;
	read.open("user_name.txt");
	if (read.is_open())
	{
		getline(read, uname);
		read.close();
	}
	else
	{
		cout << "\n Unable to open the file \n";
	}
	ifstream reead;
	reead.open("pass.txt");
	if (reead.is_open())
	{
		reead >> pass1;
		reead.close();
	}
	else
	{
		cout << "\n Unable to open the file \n";
	}
	if (uname == username && pass == pass1)
	{
		ofstream write;
		string user;
		write.open("user_name.txt");
		if (write.is_open())
		{
			cout << "\n Enter the new username : ";
			cin >> user;
			write << user;
			write.close();
			cout << "\n username successfully changed \n";
		}
		else
		{
			"\n Unable to open the file \n";
		}

		int passw;
		ofstream wriite;
		cout << "\n Enter the new password : ";
		cin >> passw;
		wriite.open("pass.txt");
		if (wriite.is_open())
		{
			wriite << passw;
			wriite.close();
			cout << "\n password successfully changed \n";
		}
		else
		{
			cout << "\n Unable to open the file \n";
		}
	}
	else
	{
		cout << "\n Incorrect username or password! Try Again : ";
	}

}
void display_specific()
{
	int id;
	cout << "\n Enter the id you want to search : ";
	cin >> id;
	if (id == s.enroll)
	{
		cout << " \n id found : \n";
		cout << " Name of the student : " << s.name << endl;
		cout << " Class of the student : " << s.Class << endl;
		cout << " Enrollment of the student : " << ptr->enroll << endl;
		cout << " Date of Birth of the student : " << ptr->b.day << "/" << s.b.month << "/" << s.b.year << endl;
		cout << " CGPA of student : " << ptr->cgpa << endl;
		cout << " Grade of student : " << ptr->grade << endl << endl;
	}
	
}