C++ dynamic array

[Twotall86]

So i have this class i am doing this code for where i have to stick the data from a outside source into a dynamic array but when i excute it and when i enter the option D it show the file all messed up and doesn't sort it. I am using xcodes on the mac and i think my problem is that its not going into the dynamic array popular is there any tips or advice?

  
#include <iostream>
#include <fstream>
#include <cstring>
#include <string>
#include <iomanip>
using namespace std;


struct Classes
{
    string names;                                                               //Holds names of the students
    string *courses;                                                            //Number of students
    int num;                                                                    //Holds the courses the student is taking
};

int main(int argc, const char * argv[])
{
    fstream fin;
    fin.open ("courses.txt");
    int size;                                                                   //Number of students
    fin >> size;
    Classes * a = new Classes[size];                                            //Array of struct which holds a students name and classes
    char el;
    fin.get(el);
    
    for (int ct = 0; ct < size; ct++)
    {
        getline (fin, a[ct].names);
        fin >> a[ct].num;
        a[ct].courses = new string [a[ct].num];                                 //Array that holds a student courses
        for ( int ct2=0; ct2 < a[ct].num; ct2++)
        {
            fin >> a[ct].courses[ct2];
        }
        fin.get(el);
    }
    cout << "Enter menu choice or Q to quit: \n";
    cout << "D to display all students and courses \n";
    cout << "S to display courses for a student \n";
    cout << "C to display students taking a course \n";
    char choice;                                                                //Variable giving the user an option
    cin >> choice;
    while (choice != 'Q')
    {
        if (choice == 'D')
        {
            cout << left << setw(20) << "Name" << setw(50) << "Courses" << "\n";
            
            for (int ct = 0; ct < size; ct++)
            {
                cout << left << setw(20) << a[ct].names;
                for (int ct2 = 0; ct2 < a[ct].num; ct2++)
                {
                    cout << a[ct].courses[ct2] << " ";
                }
                cout << "\n";
            }
            cout << "\n";
        }
        if (choice == 'S')
        {
            string sname;                                                       //Searches Name
            cout << "Enter students name: ";
            cin.get(el);
            getline(cin, sname );
            bool found = false;
            int i = 0;                                                          //Counter Variable
            while (!found && i < size)
            {
                if (a[i].names == sname)
                    found = true;
                else
                    i++;
            }
            if (found)
            {
                cout << "\n" << sname << " is taking: ";
                for (int ct = 0; ct < a[i].num; ct++)
                {
                    cout << a[i].courses[ct] << " ";
                }
            }
            cout << "\n";
        }
        if (choice == 'C')
        {
            string courses;                                                     //Searches Course
            bool enrolled = false;
            
            cout << endl << "Enter course name: ";
            cin >> courses;
            cout << endl << "Student taking " << courses << ":" << endl;
            for (int ct = 0; ct < size; ct++)
            {
                for (int ct2 = 0; ct2 < a[ct].num; ct2++)
                {
                    if (a[ct].courses[ct2] == courses)
                    {
                        enrolled = true;
                        cout << a[ct].names << endl;
                    }
                }
            }
            if (enrolled == false)
            {
                cout << endl << "No one is enrolled in " << courses << "." << endl << endl;
            }
            else
            {
                cout << endl;
            }
        }
        char x;                                                                 //Variable used to pick up the endl
        cin.get (x);
        cin >> choice;
    }
    system("pause");
   
}

course.txt
12
John Milligan
3 CIS100 CIS105 MAT113
Jill Kerning
5 CIS100 CIS105 MAT232 BIO100 ENG101
Aaron Spencer
4 CIS201 CIS225 MAT232 ENG101
Damon Hill
2 CIS334 CIS400
Kaitlyn Stamen
4 CIS100 CIS10 MAT113 BIO100
Debbie Martin
5 CIS100 CIS105 MAT232 CHY112 ENG101
Greg Nolan
2 CIS334 CIS450
Lynn Sanders
4 CIS334 CIS450 MAT250 BIO100
Alicia Thomas
4 CIS226 CIS450 MAT232 CHY112
Alan Turner
5 CIS100 CIS105 MAT232 BIO100 ENG101
Paul Henley
5 CIS100 CIS105 CIS334 ENG101 MAT232
Tim Copeland
1 CIS450

[iQChange]

This is homework? If the reply is no, use a vector instead.
www.cplusplus.com/reference/vector/vector/