#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;

int main() {
	int USERNAME = 12345;
	int PASSWORD = 12345; // variable declarations
	int overall_Grade = 0;
	char overall_Letter;
	float GPA = 0;
	bool log_Out;
	int grade[10]; // define array
	string subject[10];

	//initialize array
	for (int x = 1; x < 10; x++) {
		grade[x] = 0;
		subject[x] = "";
	}

	cout << "Welcome to the student portal. Please enter your username:" << endl;

	do cin >> USERNAME;
	while (USERNAME != 12345);

	if (USERNAME == 12345)
		cout << "Please enter your password." << endl;

	do cin >> PASSWORD;
	while (PASSWORD != 12345); // login procedure with control and loops

	if (PASSWORD == 12345)
		cout << "Thank you. Access granted." << endl;

	cout << "Welcome, student. Accessing your grades now." << endl;

	ifstream infile; // opening grades file
	infile.open("12345grades.txt");

	int subjects = 0; // determining the number of rows in the file

	infile >> subject[subjects]; // reading the first row

	do { // loop that will read the grade and subject for the next row
		infile >> grade[subjects];
		subjects += 1;
		infile >> subject[subjects];
	} while (subject[subjects] != "0");


	for (int x = 0; x < subjects; x++) // summing up the overall grade
	{
		overall_Grade += grade[x];
	}

	overall_Grade = overall_Grade / subjects; // determining the overall grade based on number of subjects in the file

	// finding overall grade
	cout << "Your overall grade is: " << overall_Grade << "%." << endl;

	overall_Grade = overall_Grade / 10;

	switch (overall_Grade) {
		case 10:
		case 9:
			overall_Letter = 'A'; // percent to letter grade conversion
			break;
		case 8:
			overall_Letter = 'B';
			break;
		case 7:
			overall_Letter = 'C';
			break;
		case 6:
			overall_Letter = 'D';
			break;
		default:
			overall_Letter = 'F';
			break;
	}

	cout << "Your overall letter grade is: " << overall_Letter << " ." << endl;

	switch (overall_Letter) {
		case 'A':
			GPA = 4.0;
			break;
		case 'B':
			GPA = 3.0; // letter grade to GPA conversion
			break;
		case 'C':
			GPA = 2.0;
			break;
		case 'D':
			GPA = 1.0;
			break;
		case 'F':
			GPA = 0.0;
			break;
	}

	cout << "Your grade point average (GPA) is: " << GPA << " ." << endl;

	if (GPA == 4.0)
		cout << "Excellent job! Keep up the great work. Make sure you take some time to relax and have fun sometimes." << endl;
	else if (GPA == 3.0)
		cout << "Great job! Keep up the great work. You're awesome, just don't be afraid to ask for help if you're struggling." << endl; // personalized suggestions
	else if (GPA == 2.0)
		cout << "Good job! We both know you can do better. Push yourself a little more, and don't be afraid to ask for help." << endl;
	else if (GPA == 1.0)
		cout << "I can see that you're struggling. We both know you can do better. Push yourself a little more to succeed and don't be afraid to ask for help. Maybe look into some tutoring." << endl;
	else if (GPA == 0.0)
		cout << "I can see that you're struggling. We both know you can do better. Push yourself a little more to succeed and don't be afraid to ask for help. Maybe look into some tutoring and talk to your teachers." << endl;

	cout << "If you're ready to log out, enter a 1. If not, enter a 0." << endl;

	do cin >> log_Out;
	while (log_Out == 0); // log out procedure with control and loops

	if (log_Out == 1)
		cout << "Thank you! Have a great day." << endl;

	return 0;
}

#include <iostream>
#include <fstream>
#include <string>

int main() {
	std::ifstream infile("12345grades.txt");

	if (!infile)
		return (std::cout << "Cannot open file\n"), 1;

	constexpr size_t MaxSub {10};
	constexpr unsigned USER {12345};
	constexpr unsigned PASS {12345};

	unsigned USERNAME {};
	unsigned PASSWORD {};
	unsigned overall_Grade {};
	char overall_Letter {'F'};
	float GPA {};
	unsigned log_Out {};
	int grade[MaxSub] {};
	std::string subject[MaxSub] {};
	size_t subjects {};
	std::string mess;

	std::cout << "Welcome to the student portal.\nPlease enter your username: ";

	do std::cin >> USERNAME;
	while (USERNAME != USER && (std::cout << "Invalid user name. Please re-enter: "));

	std::cout << "Please enter your password: ";

	do std::cin >> PASSWORD;
	while (PASSWORD != PASS && (std::cout << "Invalid password. Please re-enter: "));

	std::cout << "Thank you. Access granted.\n";
	std::cout << "Welcome, student. Accessing your grades now.\n";

	for (; subjects < MaxSub && (infile >> subject[subjects] >> grade[subjects]); ++subjects)
		overall_Grade += grade[subjects];

	std::cout << "Your overall grade is: " << (overall_Grade + .0) / subjects << "%.\n";

	switch (overall_Grade / 10 / subjects) {
		case 10:
		case 9:
			overall_Letter = 'A'; // percent to letter grade conversion
			GPA = 4.0;
			mess = "Excellent job! Keep up the great work. Make sure you take some time to relax and have fun sometimes.\n";
			break;

		case 8:
			overall_Letter = 'B';
			GPA = 3.0;
			mess = "Great job! Keep up the great work. You're awesome, just don't be afraid to ask for help if you're struggling.\n";
			break;;

		case 7:
			overall_Letter = 'C';
			GPA = 2.0;
			mess = "Good job! We both know you can do better. Push yourself a little more, and don't be afraid to ask for help.\n";
			break;

		case 6:
			overall_Letter = 'D';
			GPA = 1.0;
			mess = "I can see that you're struggling. We both know you can do better. Push yourself a little more to succeed and don't be afraid to ask for help. Maybe look into some tutoring.\n";
			break;

		default:
			mess = "I can see that you're struggling. We both know you can do better. Push yourself a little more to succeed and don't be afraid to ask for help. Maybe look into some tutoring and talk to your teachers.\n";
			break;
	}

	std::cout << "Your overall letter grade is: " << overall_Letter << ".\n";
	std::cout << "Your grade point average (GPA) is: " << GPA << ".\n";
	std::cout << mess;
	std::cout << "If you're ready to log out, enter a 1. If not, enter a 0: ";

	do std::cin >> log_Out;
	while (log_Out != 1 && (std::cout << "Enter 1 to log out: "));

	std::cout << "Thank you! Have a great day.\n";
}