Croepha's guide to computer programming [VERY EARLY DRAFT EVERYTHING SUBJECT TO CHANGE]

Chapter_000_Introduction.cpp

/*
TODO: Need to work on language so that ESL and Children would have easier time reading

Summary Paragraph:

This is a guide for people who have little or no computer programming
experience but aspire to create excellent and high quality software. 
We will cover everything to get you started, including getting your 
computer ready for programming and talking about some basic concepts.
Eventually we will work our way onto making quite sophisticated programs.
Although we use C++ as a language, we don't focus on a comprehensive set
of its features, instead we address programming concepts in general.

Although you don't have to be really good at math to be a good computer
programmer, before you start this tutorial you should at-least have a
basic understanding of algebra, as I expect you do know things like 
what a negative number is, and how to solve for unknown values of
simple equations. You should also have some basic computer kills, and
be able to install software and change system settings on your computer.
<possible plug of a "algebra for computer programmers tutorial?">

Chapter 0: Introduction

This is a tutorial for people who want to become highly skilled.  This
is a guide for people who are concerned about getting the most reliability
and performance out of their applications, this is not a guide for people
who just want to make websites or make some quick scripts here and there.
Also this isn't for people who want to make an application as fast as
possible with out concern for quality.  If you just want to make something
fast then there are other things for you.  This guide alone won't get you
to the point of being a master programmer, but it will help you get started.

This tutorial assumes no prior-knowlege of computer programing however having
general computer skills and a basic understanding of Algebra would be good
to have.

TODO: Not everyone can become a programmer.  Being good at computer programming
requires a strong passion.  Good computer programmers are people who write a
ton of code, every day. They write code for work and they also write code on
their personal time.  

A programmer's job is to take tasks that we think about, and convert into a
form that a computer can understand them.

To illustrate, I want you to think of an old calculator.
<insert image of calculator>

The calculator really only understands a specific number of instructions, like:
  "insert a digit to the number"
  "add this number"
  "divide this number"
  "clear"
  etcetera


This is different from the way that people think, we generally think like:
  "How many pounds of flour do I need to bake cookies for this weekend?"
  "When do I need to get up tomorrow in order to not be late for work?"

When you use a calculator, you are essentially programming it with instructions.
Can you see the difference?  Computers are actually really dumb
compared to people.  The main advantage that computers have is that
they can reliably do large amounts of simple tasks very quickly.

The difference between the calculator instructions and the way that
people think is often referred to as Low Level and High Level respectively.

Computers can actually do high level tasks closer to how people think
about things, but that is after a programer has already done the work
of converting those high level concepts into low level instructions.
Later, we will talk more about high and low level, because eventually
we will be making our own high level code!

Here is another example:  Bob and Alice are throwing a suprise
birthday party for Charlie.  Bob needs to get some snacks from the
store and Alice needs to trick Charlie into coming to the party.
<TODO: This needs work, too tired to come up with a better analogy>

Here you can see, that another part of programming is sort of like
telling a story.  You have to keep in your mind all of the elements
of the story and the proper sequence of events to get the desired 
results.

In this tutorial we are going to be programming in C++ but we won't
really be diving into a lot of C++'s features, so in a way our code
will be more like C than C++.  I don't fully expect for you do know
what C or C++ is or means at this point, but I want you keep that in
the back of your mind as the name of the language we are programming
in incase you want to do your own research on things later on.  Also
what I mean by a computer "programming language" is just the
specification of how you write the instructions for the computer.

This is what our code will look like:
"HelloWorld.cpp" */
#include <stdio.h>
int main() {
    printf("Hello World\n");
}  

/*
This is called a "Hello World" program because all it does is output
the text "Hello World".  This is a very small and basic computer
program that is usually one of the first programs that a computer
programmer will learn how to write.  Its also a good bit of code to
start with just to make sure that the compiler is working right.

One thing I want to mention before we move on, is that other programmers
that you will meet will probably do things differently than how I
recommend doing them here, and that is absolutely fine!  There are many
different tools and styles to chose from and I think that some point
you should take it upon yourself to try many of them.  But this guide
assumes that you have installed and use the programs and methods that
I recommend in this guide, and I think that what I recommend here is a
good starting point.

You will want to know how best to talk to people in the community.
As part of following this tutorial you may run into situations where
you need help, or maybe you just want to share something clever you
came up with!  <talk about forums and discord here>
(TODO: Is discord/irc an issue because its not always family friendly)

The next thing we need to do is get your computer setup to do programming!

This next step will be different depending on whether or not you are
running Windows, MacOS, or linux.

*/

Chapter_001A_Setup_A_Windows_PC_For_Programming.cpp

/*
GIST NOTE:
Below it talks about a tutorial bundle, that is this:
https://www.dropbox.com/s/y8fcfhkb2ition8/Chapter_001A_MSWIN.zip?dl=0

Chapter 1A: Setup a Windows PC For Programming:

Download the text editor: Here I recommend GNU Emacs for windows.  Grab it
by going to this URL: http://mirrors.syringanetworks.net/gnu/emacs/windows/
and choosing the highest version number: 

Download the compiler, "Clang" From here: http://releases.llvm.org/download.html
Again grab the highest version number and you want the Pre-built binaries for
Windows 64bit

Double click the LLVM exe file to install LLVM which include clang
- select "Add LLVM to the system PATH for all users"

https://www.visualstudio.com/vs/older-downloads/ make an account
Download and install Visual Studio Community 2013 with Update 5
Install visual studio, feel free to unselect all of the optional
packages, we don't need them.

Extract the Emacs ZIP file that you downloaded, I recommend extracting
it into your C:\ Drive.  Once you extract it, find bin\runemacs.exe
Right click runemacs.exe and click Send To > Desktop (Create Shortcut)
This will put an icon on your desktop, and we will use it a lot

In the tutorial bundle, find the MSWIN folder, and double click the
install.bat file.

Also I highly recommend going into folder options and:
  Enabling Show hidden file, folders, and drives
  Disabling Hide extensions for known file types

Now that we got your computer setup, lets compile our first program!

Now run emacs for the first time, using the shortcut on the desktop.

Click the Open/Create file button at the top

Navigate to a place on your computer that you want to store the files
for this program.  Your "Documents" folder is generally a good place
for this. Then click the new folder icon at the top, and make a folder for this
project.  "Chapter1" might be a good name.

Once you are in your new folder you need to enter in the names of
files we need to create.  First create a file called build.bat by
entering "build.bat" into the file name box and hitting open.

Now emacs will show at the bottom that you have "build.bat" open.
There are two different sides of emacs, so that you can have two
things open at a time.  So build.bat will be in one of the sides.
Build.bat should be completely blank because it's a new file.

Enter in the text:

clang++ -D_CRT_SECURE_NO_WARNINGS hello_world.cpp -o hello_world.exe

So, emacs will use build.bat to do the compiling. We will go into
further detail on what build.bat is, and what things we can do
with it, but for now, you should just note that we are compiling
"hello_world.cpp" and the output (our compiled program) will be
"hello_world.exe"

So "hello_world.cpp" doesn't exist, lets fix that.  Use the
Open/Create File option we used earlier and it should already
have you in your project directory.  Now enter "hello_world.cpp"
into the file name field and hit open.

Now Copy and paste the hello world source code from chapter 0
into the "hello_world.cpp" file.  Then hit the compile button.
If everything went well so far, you should see a green "finished"
with some text that popped up in one of your sides in emacs.
This new test is called your compilation buffer.  We will talk
more about this later.

Note: If you did not see a green "finished" then something is wrong.
Please double check to make sure that you followed the directions
correctly.  If you still cant figure it out, jump over to handmade
network and get some help :)

So we have compiled our program but we have no run it yet.  To
run our program, we need to open up a console.  In the top
menu bar of emacs, there should be a button that says
"Open Console".  Click it, and a window command console
should pop up.  In that console, type "hello_world.exe" and then
hit return.


There you go! You have now successfully compiled and run your first
program.  Go to chapter 2 to learn more about the source code that
we just compiled
*/

Chapter_002_Foundations.cpp

/*

In the last section I mentioned the concept of "compiling" your program,  We
will go into more detail with what this means later, but for now I'll just
say that this just means that a program called a "compiler" is translating
the source code from text (what your text editor works with) into a binary
file that contains machine code (What your processor understands)

One importaint thing to know, is that when you are compiling, any errors that
are in your program will shown on one side of your editor.  These errors will
have number in them that indicate what line the error is on.  These errors will
have some sort of hint to help you fix the problem but sometimes they aren't 
as helpful as we would like.  If you ever want to know what an error means,
then you should ask a tutor to help you.

Now that you have all of your tools installed and you have successfully
compiled and run your first program lets look at the code.
For now we are going to ignore these parts:
*/
#include <stdio.h>
int main() { ... }    
/*
And we will just focus on what is between those curly brackets ({}).
Don't worry, we will cover everything we skip now in a lot of depth later.
*/
// This line here will output the words: Hello World.  You are actually
// Calling a function called "printf".  We will talk about functions later
// but for now just understand that printf represents some code that you
// telling the computer to execute that exists elsewhere
printf("Hello World\n");
/* The "\n" is a hidden bit of text that instructs the console(terminal)
   to make a new line.  If you aren't sure what this means, then try to
   compile and run a program that doesn't have the "\n" and see what I
   mean!  The "\n" has a special name: The New Line Character :)
   If your output looks jumbled up, then you might be missing some
   New Line characters.
The one importaint thing to know at this point is that everything inside of
those curely brackets are instructions that the computer will execute in
sequence, starting at the top and working down.
Look at this program:
*/
#include <stdio.h>
int main() {
   printf("One ");
   printf("Two\n");
   printf("Three ");
   printf("Four\n");
   printf("Five ");
   printf("Six\n");
}    
/*
Can you guess what the output will be without running it?
Go ahead and run it and find out if you were right!
NOTE: When running new code, feel free to overwrite your
old code if your don't care about it.  For example your
Hello World code might not be that important so you
can just edit the code in place and recompile and rerun
it to get a new result.  Eventually you will get to the
point where you are doing that all the time!  You can also
of-course just make a new source and build file in a new
directory and that way your new code doesn't replace your
old code.   You can also just append to your existing code.
PRO TIP: When you are using the console or terminal, you
can press the up arrow on your keyboard to bring up the
last command that you pressed, this helps out a lot when
you are running the same command over and over again :)

From now on, when you see code samples, you should run them
before moving on.  And if you are confused about what
you are seeing, then you should ask for help, please don't
skip anythin.  And remember, everyone has their own pace :)

When you ran the code did it do what you guessed it would do?
If you are confused about the outcome ask a tutor for help.
If you guessed differently, can you change the program so
that it does what you had expected it to do?

- - -

Alright, now we are going to try something new:
Try running this code: */ printf("Some number: %d\n", 123);   /*
Neat huh?  The "%d" is called a "conversion specification".
What this means is that %d tells printf that we want to convert
a number into text.  More specifically we are converting an "int"
into text.  An "int" is a specific type of number.  It is actually
short for "integer".
Text "123" is different from the number 123 in a subtle but
important way.  As far as the computer is concerned the text
is just the idea that there is "1" followed by a "2" then
followed by a "3"  Where as the number is stored in a way
where the computer can actually do math on it.  Down the
road we will talk about how exactly your computer works with
each type
And as you probably expected, we can also do math: */
printf("Math!  %d\n", 23 - 4);
printf("More Math: %d\n", 26 / 2 - 4 * 5);
/* 
Because of the way that computers work an int can
have a lowest value of −2,147,483,648 and a highest
value of 2,147,483,647.  Going outside of those limits
the value will actually wrap around.  To illustrate what
I mean, check out this code: */
printf("Largest int:  %d\n", 2147483647);
printf("Largest int + 1:  %d\n", 2147483647 + 1);
/*
This is called an "integer overflow." There are other types
of overflow that we will learn about later.  Overflow is
generally considered something to avoid because it can
lead to your program doing things that you didn't expect.
But if you are expecting it then it can actually be
considered a useful feature in certain situations. Later
on we will talk about why there are min/max limits.
We can also store numbers in a way that we can refer to
them in multiple operations.  Check out this code: */
int my_number; // This declares the variable
my_number = 4; // This assigns a value to the variable
printf("1) My Number: %d\n", my_number);
my_number = my_number + 2;
printf("2) My Number: %d\n", my_number);
my_number = my_number / 2;
printf("3) My Number: %d\n", my_number); /*
Variable names can't have spaces in them, and they
can't start with number.  They can only have numbers
and letters and the underscore (_).
We can also ask the user for input. Try the following code: */
 int number_from_user;
 printf("Enter a number:");
 scanf("%d", &number_from_user);
 printf("This is your number multiplied by 2: %d\n", number_from_user *2); /*
Here we introduce a new function, "scanf", this is the
opposite of printf, instead of producing output, it
lets us process some input from the user. Notice the
ampersand (&)? thats a special notation. its called
the "address of" operator.  We will learn more about
that later, but for now just know that its useful
here because it allows another function to alter a
variable that we specify. Here is more complex example: */
int num1, num2, num3;  // Multiple variables of the same type can be declared at the same time
printf("Enter number 1:");
scanf("%d", &num1);
printf("Enter number 2:");
scanf("%d", &num2);
printf("Enter number 3:");
scanf("%d", &num3);
printf("sum: %d\n", num1 + num2 + num3);
printf("product: %d\n", num1 * num2 * num3); /*
Feel free to play around with this.  Can you come up
any cool things? can you automate some math problems? 
Expirement if you want before moving on.
- - -
Remember when I said that the lines between the curly brackets
get executed in order? Well... I kinda lied (not going to be
the last time...)
Below are two new things, goto and labels.  Labels are ways
to reference specific places in your code.  goto is a special
thing that tells the computer to just jump to that place instead
of going to the next line as it would normally.
Check out this code: */
goto middle;
top:
printf("line 1 !\n");
goto bottom;
printf("line 2 !\n");
middle:
printf("line 3 !\n");
goto top;
printf("line 4 !\n");
bottom:
printf("line 5 !\n");   /*
What do you think this code will do?
Try it out and see if you are right.  Are you confused it?
if so then ask a tutor for help.
NOTE: When working with goto and labels, be careful not cause
endless loops, if you make one you can always kill your program
by pressing Ctrl+C in the terminal or console.
- - -
Alright now I want to show you something new.  Run this: */
printf(" 2 < 5 : %d \n", 2 < 5 );
printf(" 5 == 5 : %d \n", 5 == 5 ); 
printf(" 1 || 0 : %d \n", 1 || 0 );
printf(" 0 && 0 : %d \n", 0 && 0 );
/* Run the above code before moving on.

Neat huh?  These are the relational operators, they compare
   two numbers:
  ==   !=	>   <    >=    <=
  
These are the logical operators:
  &&   ||    ! 
I want you to write some code to play around with these different
operators and I want you to figure out what each does.  The (!)
operator is special in that it only deals with one value, whereas
all the other operators work with two values.  Think of the (!)
as being similar to a (-) infront of a negative value.
Have you tried each operator out yet?
When playing with the relational operators, make sure that you
try cases where the values on each side are the same, and also
try different values, and also see what happens when you swap
sides.
When playing with the logical operators make sure that you try
zero with each operator.
Have you figured out what each operator does?
While you are playing with the code I want you to try this out: */

int v1, v2;
printf("Enter two numbers (press the enter key after each number):\n");
scanf("%d", &v1);
scanf("%d", &v2);
printf(" %d <  %d evaluates to: %d \n", v1, v2, v1 <  v2 );
printf(" %d <  %d evaluates to: %d \n", v2, v1, v2 <  v1 );
printf(" %d >  %d evaluates to: %d \n", v1, v2, v1 >  v2 );
printf(" %d >  %d evaluates to: %d \n", v2, v1, v2 >  v1 );
printf(" %d == %d evaluates to: %d \n", v1, v2, v1 == v2 );
printf(" %d == %d evaluates to: %d \n", v2, v1, v2 == v1 );
printf(" %d != %d evaluates to: %d \n", v1, v2, v1 != v2 );
printf(" %d != %d evaluates to: %d \n", v2, v1, v2 != v1 );
printf(" %d <= %d evaluates to: %d \n", v1, v2, v1 <= v2 );
printf(" %d <= %d evaluates to: %d \n", v2, v1, v2 <= v1 );
printf(" %d >= %d evaluates to: %d \n", v1, v2, v1 >= v2 );
printf(" %d >= %d evaluates to: %d \n", v2, v1, v2 >= v1 );
printf(" %d && %d evaluates to: %d \n", v1, v2, v1 && v2 );
printf(" %d && %d evaluates to: %d \n", v2, v1, v2 && v1 );
printf(" %d || %d evaluates to: %d \n", v1, v2, v1 || v2 );
printf(" %d || %d evaluates to: %d \n", v2, v1, v2 || v1 );
printf(" !%d      evaluates to: %d \n", v1, !v1);
printf(" !%d      evaluates to: %d \n", v2, !v2);

/*
  
Alright once you feel that you have played around enough to know
what each operator does, take a look at the following table:
Operator  Test description
  ==      equality
  !=      inequality
  >       greater than
  <       less than
  >=      greater than or equal to
  <=      less than or equal to
  &&      logical "and", are both sides are non-zero?
  ||      logical "or",  are one of the sides non-zero?
  !       logical "not", is the value to the right zero?
If the test is true, then the result is a 1 else it is a 0.
In programming we generally talk about this as true meaning
non-zero, and false is always zero.  A negative number is
always true.  Programmers sometimes call statements that deal
with true or false values: Boolean.
  
/* 
Here is another new thing: if.  "if" tells the computer to
make decisions.  It allows you to run code /if/ a condition
is met.  Look at this code: */
if (5 > 3) printf("5 is bigger"); /*
Can you write a program that takes two numbers and prints out
which one is bigger?
Go ahead and try it.  If you get stuck remember you can ask for help.
Once you have tired to write the program proceed:
This was my solution to the problem: */
int num1, num2;
printf("Enter two numbers (press the enter key after each number):\n");
scanf("%d", &num1);
scanf("%d", &num2);
if (num1 > num2) printf("%d is bigger\n", num1);
if (num2 > num1) printf("%d is bigger\n", num2); /*
If your solution is different then thats good.  There are many
ways to write code that does the same thing.

- - -

Alright, now it is time for a chalenege:

I want you to use the tools that we learned in this chapter to 
write a program that asks for a number and then prints out 
every number between 1 and that input number and you are
allowed to only have one line of code that has "printf" in it.

Dont scroll down until you have attempted it.

If you are having trouble, here is a hint:
You can have a goto at the end of your if statement

If you have attempted it but still cant get it to
work right, then find a tutor to help you out.  Make
sure that you have some code that you have made and 
share it with your tutor so that they can look at 
it and see if it has any issues.

Dont scroll down until you have completed the assignement.

Second challenge:

I want you to make a simple guessing game.  I want
you to come up with a secret number and put it 
into your code and then your code will ask the
player to make a guess as to what that number is.
Your problem must tell them if they got it right
or if their number was too low or too high.

Please attempt the challenge now.

If you are having trouble please ask a tutor for help.

Dont scroll down until you have completed the assignement.













So I want to show you a few new things before we
wrap up this lesson.

For the first chalenge above this was my solution:
*/
int counter, end;
printf("Enter number to count to:\n");
scanf("%d", &end);
i = 1;
start:
printf("Number: %d\n", i);
i=i+1;
if (i<end+1) goto start;
/* 
If your solution looks different then that is fine :)

I want to show you a little trick, run this: */
int i, end;
printf("Enter number to count to:\n");
for (i=1; i<end+1; i=i+1) printf("Number: %d\n", i);
/*
Neat huh :) 

Also You can use curly braces to group code together. For example: */
int i, end;
printf("Enter number to count to:\n");
scanf("%d", &end);
for (i=1; i<end+1; i=i+1) {
   printf("Number: %d\n", i);
   printf("Number again: %d\n", i);
}
/* Run that.

- - -

This was my solution second challenge: */
int secret_number, guess;
secret_number=42;
start:
printf("Enter your guess:\n");
scanf("%d", &guess);
if (guess==secret_number) goto end;
if (guess> secret_number) printf("Your number is too large\n");
if (guess< secret_number) printf("Your number is loo low\n");
goto start;
end:
printf("You guessed correctly!\n");
/*
Check this out: */
int secret_number, guess;
secret_number=42;
printf("Enter your guess:\n");
while(guess!=secret_number) {
scanf("%d", &guess);
if (guess> secret_number) printf("Your number is too large\n");
if (guess< secret_number) printf("Your number is loo low\n");
}
printf("You guessed correctly!\n");
/*
These are called for and while loops, they are just ways to
do the same thing as goto, but they are a little easier to 
read.  Most people discourage the use of goto and prefer
the use of these loop constructs.
Also one more thing, there is a special code called "break".
If you put break; into one of those loops, it will stop the
loop from running. So you could have done this instead: */
while(1) {
if (guess> secret_number) printf("Your number is too large\n");
if (guess< secret_number) printf("Your number is loo low\n");
if (guess==secret_number) break;
}
/*

Now you have learned the basics of computer programming! 


*/

Chapter_003_Computer_Math.cpp

/*

Computers do math a little bit differently then you and I would.
People use numbers that are called "Base ten" what this means is
that each digit can store the value of zero through nine (ten different 
values)  Base ten numbering evolved naturally for people because 
we have ten fingers and it is easy to count on your fingers so 
thinking of things in terms of tens is natural.

For computers the natural number system is called "Binary" or
"base 2" Computer's use base 2 because storing something as either
a one or a zero is the more reliable way for computers store 
information.  If a computer tried to store any value in-between
that value would drift over time.

One digit in binariy is called a "bit".  Bits are usually put
together in groups of eight called bytes.  Ony byte can store
any value from 0 to 255.

*/