File IO - Binary file.read program

//********************************************/
// Author: David Hill
// Description: This program is  confusing
//********************************************/
#include <iostream>
#include <iomanip>
#include <fstream>
#include <cstring>

using namespace std;

struct Student
{
	char firstName[16];
	char lastName[16];
	char major[4];
	double GPA;	
};

// Defining Functions
void stdSORT(Student [], int);	// Option 1
void stdSEARCH(Student [], int);	// Option 2
void searchGPA(Student [], int);		// Option 3
void exchange(Student, Student ); // the extra "cup"


int main(int argc, char *argv[])
{
	int choice;			// Menu choice
	int count;			// To count number of students
	int i;
	
	
	// File Operations
	fstream file;
	file.open(argv[1], ios::in | ios::binary);

	file.read(reinterpret_cast<char *>(&count), sizeof(int));

	
	Student *STRUC = new Student[count];

	for (i = 0; i < count; i++)
	{
		file.read(reinterpret_cast<char *>(&STRUC[i]), sizeof(Student));
		
	}
	
	if (count < 0)
	{
		cout << "Error! No students detected in file\n\n";
		exit(-1);
	}
	else if (!file)
	{	
		cout << "File did not open, please try again.\n\n";
		exit(-1);
	}


	for (i = 0; i < count; i++)
	{
		file.read(reinterpret_cast<char *>(&STRUC[i]), sizeof(Student));
	}

		while(10)
		{
			cout << "Please Select an Option: " << endl;
			cout << "1. List the students sorted by last name" << endl;
			cout << "2. Search the students by last name" << endl;
			cout << "3. List students with more than certain GPA" << endl;
			cout << "4. Quit the program" << endl;
			cin.ignore();
			cin >> choice;
		
			while (choice < 1 || choice > 4)
			{
				cout << "Invalid option, please choose a new one: ";
				cin >> choice;
			}
		}
	


		switch (choice)
		{
			case 1: stdSORT(STRUC, count);				
				break;
			case 2: stdSEARCH(STRUC, count);
				break;
			case 3: searchGPA(STRUC, count);
				break;
			case 4:
				return 0;
		}



}

void stdSORT (Student STRUC[], int count)
{
   for (int i = 0; i < count-1; i++)
   {
      for (int j = 0; j < count-1-i; j++)
         if (strcmp(STRUC[j].lastName, STRUC[j+1].lastName) >= 1)
            exchange (STRUC[j], STRUC[j+1]);
		
		
		
   }
   cout << "The student's listed in alphabetical order:" ;
	for (int i = 0; i < count; i++)
		{
		cout << STRUC[i].lastName << "\n";
		cout << endl;
		}
}		

void exchange(Student S1, Student S2)
{

	Student extra;
	extra = S1;
	S1 = S2;
	S2 = extra;
}

void stdSEARCH(Student STRUC[], int count)
{
	bool flag = false;
	char stdsearch[16];

	cout << "What is the Last Name of the student you would like to search? ";
	cin >> stdsearch;
	
	for (int ctr = 0; ctr < count; ctr++)
	{
		if (strcmp(stdsearch, STRUC[ctr].lastName) == 0)
		{
			flag = true;
			cout << STRUC[ctr].firstName << endl;
			cout << STRUC[ctr].lastName << endl;
			cout << STRUC[ctr].major << endl;
			cout << STRUC[ctr].GPA << endl;
	
		}
		
	}
	if (flag == false)
	{
		cout << "Student is non-existent. Please Try again.";
		exit(-1);
	}	
	
	
}	

void searchGPA(Student STRUC[], int count)
{
	double GPAsearch;
	
	cout << "Please enter a GPA you wish to search: ";
	cin >> GPAsearch;
	while (GPAsearch < 0.0 || GPAsearch > 4.0)
	{
		cout << "Invalid GPA. Please enter again: ";
		cin >> GPAsearch;
	for (int i = 0; i < count-1; i++)
		{
			STRUC[i].GPA > GPAsearch;
			if (STRUC[i].GPA > GPAsearch)
			{
				cout << STRUC[i].firstName << "'s GPA: " << STRUC[i].GPA << endl;
			}			
		}
	}	


}