----------------------------------------------------
Pointers
----------------------------------------------------
| This uses a pointer to loop through the chars
| in a char array (string).
| 'text[80]' is the char array.
| '*textPtr' is the pointer.
| 'textPtr++' is pointer incrementation, which
| just means it advances to the next memory location
| which in this case will be the next array element
| which will be the next char in the string. It does
| not increase by byte, but rather by the size of the
| data type.
-----------------------------------------------------
*****************************************************

#include <iostream>
using namespace std;

void main(){
	
	char text[80];
	char *textPtr = NULL;
	
	cout << "Please enter a string: ";
	cin >> text;

	textPtr = text;

	while (*textPtr){
		cout << *textPtr << endl;
		textPtr++;
	}

}

********************************************************

--------------------------------------------------------
Structures
--------------------------------------------------------
| This creates a structure called Point(x/y coord point)
| then initializes a new 'Point', sets its values, then
| displays the values.
--------------------------------------------------------
********************************************************

#include <iostream>
using namespace std;

struct Point {
	int x;
	int y;
};


void main(){
	Point pt1;

	pt1.x = 1;
	pt1.y = 2;
	cout << "(" << pt1.x << ", " << pt1.y << ")" << endl;
}

********************************************************


--------------------------------------------------------
Linked Lists
--------------------------------------------------------
| This code creates a structure named 'Employee' and
| initializes a new instance of it, sets its values. By
| setting its '*next' value to NULL is like ending the
| list. This code creats a linked list that has only one
| item in it.
| Use '->' like '.'
--------------------------------------------------------
********************************************************

#include <iostream>
using namespace std;

#define STRING_LENGTH 32

struct Employee {
	char firstName[STRING_LENGTH];
	char lastName[STRING_LENGTH];
	Employee *next;
};

void main(){
	Employee *employee = NULL;

	employee = new Employee;
	
	strcpy(employee->firstName, "Jonathan");
	strcpy(employee->lastName, "Brenner");
	employee->next = NULL;

	cout << employee->firstName << " " << employee->lastName << endl;
}

********************************************************


--------------------------------------------------------
OK the big one
--------------------------------------------------------
Alright, this code has a lot to it.

First, 'struct Employee':
	Think of this as an object with properties or
	a very small class with only variables.
	I think of the '*next' variable as a 'doorway'
	to a new room that contains the four values.
	Van Gorp used the metaphor of a train, as in
	the structure is a 'boxcar' with the values in
	it, and '*next' as the 'hook' that two cars are
	connected by. Whatever works for yuh.

Next, the 'insert' function:
	- The '*empList' parameter, passed as a pointer,
	is basically the linked list, it points to the
	location of the first item in the list, so its
	the 'front door' or the 'engine car'. That is
	why its the 'current node' because it starts
	with the first item in the list. (you could call
	them items instead of nodes as well, Gorp used
	nodes).
	- The '*node' parameter is the item or node to be
	inserted into the list, so think of the function
	as insert(list_to_add_node_to, node_to_add_to_list)
	- The nodes are NULL until assigned a value, so
	in 'if' statments, empty 'items' will = 'false'
	- The 'if' block after the 'while' loop is just
	to determine where to insert the item in the list
	these can be confusion, but know that they are
	completely optional. They are use in this code
	to sort the list as items are added to it.
	- After the item has been entered, the function
	returns the 'updated' list or rather.

Next, the 'findEmployee' function:
	- The '*empList' parameter is the list to search
	and the 'parNumber' is the employee number that
	the user entered to search for.
	- '*curNode' is, again, the equiv of the first
	item in the list. So anytime you see that line
	'Datatype *someVar = linkedList;' you can think
	of it as 'starting from the first item..."
	[if thats confusing completely ignore it]
	- 'if (!found)' if the current item's 'number'
	value does not match the value being searched
	then continue through the list to the next item
	By setting the current node to the current node's
	'next' value, you are changing which item the
	program is looking at. So that line of code is
	like: stop looking at this item(curNode) but 
	rather look at the item after(curNode->next)
	- If the employee is found, then the function
	returns the curNode, but since its returned as
	a pointer, its really returning the location of
	the item in the list, and then the program uses
	that info to go find the values later.
	- 'display' just simply starts from the first
	item in the list and spits out all the values
	for each item.

Now for 'main()':
	- 'empNumber' will just be the holding variable
	for the number the user will search.
	- fstream requires you to include <fstream>
	- inFile(file_name, IO_type)
	- BUF_SIZE can be any value you want
	- buffer is just an array that will hold each
	char from the file. (Name it whatever you want)
	- '*empPtr' is just like '*curNode'
	- The !inFile just means if the file stream
	is unavailable (ie: file's not open, no read/write
	permissions, ect)
	- The do loop creates a new item, sets the values
	using the vals from the file, then by setting its
	next val to NULL, it means that empPtr is only a 
	single item and not a list. Then since insert()
	returns the updated list, then the empList is
	set to that list
	- Loop goes till it can't read a new line
	- getline(array_to_read_chars_into, num_chars_to_read, char_to_stop_reading_at)
	- 'display' the now updated list
	- ask the user to enter a number to search for
	- The '*foundEmployee' initialization should
	make scense by now.
	- Finally, just dispay the vals of the employee
	that was found.
--------------------------------------------------------
********************************************************

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

struct Employee {
	string firstName;
	string lastName;
	unsigned long number;
	double salary;
	Employee *next;
};

Employee* insert(Employee *empList, Employee *node){
	Employee *curNode = empList;
	Employee *prevNode = NULL;

	//Sort by employee number
	while (curNode && node->number > curNode->number){
		prevNode = curNode;
		curNode = curNode->next;
	}

	if (!curNode && !prevNode){
		empList = node;
	}
	else if (!prevNode){
		node->next = curNode;
		empList = node;
	}
	else if (!curNode){
		prevNode->next = node;
	}
	else {
		node->next = curNode;
		prevNode->next = node;
	}

	return empList;
}

Employee* findEmployee(Employee *empList, unsigned int parNumber){
	bool found = false;
	Employee *curNode = empList;

	while(curNode && !found){
		found = (curNode->number == parNumber);
		if (!found)
			curNode = curNode->next;
	}

	return curNode;
}

void display(Employee *empList){
	Employee *curNode = empList;

	cout << "***************************************" << endl;
	while (curNode) {
		cout << "---" << endl;
		cout << "First Name: " << curNode->firstName << endl;
		cout << "Last Name: " << curNode->lastName << endl;
		cout << "Number: " << curNode->number << endl;
		cout << "Salary: $" << fixed << setprecision(2) << curNode->salary << endl;
		cout << "---" << endl;
		curNode = curNode->next;
	}
	cout << "***************************************" << endl;
}

void main(){

	unsigned int empNumber;

	fstream inFile("employees.dat", ios::in);
	const unsigned int BUF_SIZE = 128;
	char buffer[BUF_SIZE];

	Employee *empPtr = NULL;
	Employee *empList = NULL;

	if (!inFile) {
		cerr << "Input file not opened." << endl;
		exit(1);
	}

	do {
		empPtr = new Employee;
		inFile >> empPtr->firstName;
		inFile >> empPtr->lastName;
		inFile >> empPtr->number;
		inFile >> empPtr->salary;

		empPtr->next = NULL;
		empList = insert(empList, empPtr);
	} while(inFile.getline(buffer, BUF_SIZE, '\n'));

	display(empList);

	cout << "Find an employee by number: ";
	cin >> empNumber;

	Employee *foundEmployee = findEmployee(empList, empNumber);

	if (foundEmployee){
		cout << endl;
		cout << "----------(" << foundEmployee->number << ")----------" << endl;
		cout << " " << foundEmployee->firstName << " " << foundEmployee->lastName << endl;
		cout << " $" << fixed << setprecision(2) << foundEmployee->salary<< endl;
		cout << "---------------------------" << endl;
	}
	else {
		cout << "No employee was found." << endl;
	}

}

********************************************************