[DSA] template class

Template, as the name suggested is a standard or generic way/form we could use for creating different output. For an example, you would ask for a report template from your senior so that you more or less know how what is expected from you.

One of the benefits of programming through a template, it reduces the effort to recode the same function/class but pass in a different variable type. Our good friend the STL Algorithms is the best example of programming template. Imagine the sort() function need to be rewrite again and again and again for each type of variable...............

I strongly do not advocate of getting report from other people and change it to your name. That is not template nor referencing. It is called plagiarism.

A function template or class template, beside used with primary variable, eg int, char, double. It can be used with data structures too. As usual, it is possible to pass in more then 1 parameter of the same or different variable type to the function template or class template.

reference the code below. NOTE: The Code is NOT COMPLETE you need to fix it before you could use it.

Q1. What does both of the function trying to do??? Is there a way to generalize it without repeating the "same" code?
Q2. Populate the given code with a template function that will double each number stored as elements in the data structure. Is it possible to double a char or a string stored in the data structure??

//===CHALLENGE==> HEROES ONLY=====//
Q3. Write a template function reverselist() that could take in a list display the content of the list and store the contents of the list on to a stack and later display the content of the stack.
Q4. Is there a more efficient way to create a test for a palindrome????

[DSA] File Op

Data need to be saved somewhere. The reason being, if all data are stored in memory and the computer get accidentally turned off. The effect would be epidemic!
Data output using fstream are clear text by default! ENCRYPT any sensitive info before output to file!!!!!

Some text file are delimited in a certain way, for example below.
sample of comma delimited file=> aa,bb,cc
sample of semicol delimited file=>aa;bb;cc

File operations of the program, should be able to read in the lines, and "parse" the input accordingly and stored into the required variable.

This usually happens when legacy software needed an upgrade to the most-IN technology (Programmer Guru Mantra= If it ain't spoil, don't fix it). However, the data are not compatible. One common feature of software, it has the ability to "dump" data out of the system.

As as programmer, we need to write code to extract those that required to the new system. Therefore, we still get to keep our jobs, make ourself valuable.

Regarding on the issue of Out Sourcing to other country. Fret Not. Why would the company would entrust their data to a 3rd party other then their employer? The audit trail of hands dipped into the data would be clearer and easier to trace. Hence the accountability.

With Great monies, comes great responsibilities.

Talking about file IO and security, take a look at the game below.
http://www.takegame.com/logical/htm/boxworld.htm

I played the game when i was still a teenager like most of you. My friend challenged me to complete the game (eg Lvl 99) in the shortest possible time. Few of us, being kiasu (hokkien colloquial for afraid to loose), keep comparing each other's progress. Me, for being me went to my usual corner and gave my friend Lvl99 at the end of the day. Guess how I manage to get it done????

Homework
The sample of file operations are in the writescore.cpp and readscore.cpp. Compile and run it to get a feel of how File I/O is done.

Drill Questions
1. Write a program that READS IN records (eg A.txt) that are semicol delimited eg
tom 19 dcpe/2B/01 DSA B+;kelly 18 dcpe/2B/01 DSA A; .....

2. Write a program that WRITE OUT records (eg B.txt) that are semicol delimited eg
tom 19 dcpe/2B/01 DSA B+; kelly 18 dcpe/2B/01 DSA A; ....

3. write a program that reads in Q1 but modifies to comma delimited and output to a new file.

HINT: It is good to have a menu driven system to choose between the options instead of running 2 cpp projects concurrently.

[DSA] Class & Objects

In programming, class is a common topic. No matter is C++ or Java, the same concept on class still applies. Killing N birds with 1 stone.

In programming, objects are end product of a class. Objects represent data that are generalized by the class.

Think of the Class as a cookie cutter, Objects are the cookies, the dough is generic material that all cookie need to use. Each object may have some unique attribute(s), such you would sprinkle some chocolate on the dough to make a chocolate chip cookie or add some almond to it almond cookie. In the generalization point of view (the class pov), it is still cookie. All cookie uses the same dough.


Think about it, I went to eat dim sum http://en.wikipedia.org/wiki/Dim_sum last weekend and realize some of the items taste the same. I wonder they use the class method to make it. I.e generic minced meat to make dim sum of different shapes.

How would data be generalized and yet representable?
For an example, Cats and dogs. Both are mammals. Both have four legs. Does it means that the cat is a dog and vice versa???!!! Sure we can think of some other attribute that differentiates a dog and a cat. dog barks and cat meows.

So we can have a class named pets, we can have data attribute of pet type, pet breed etc. Below is the sample code for inventory I have for the dog class for my imaginary dog kennel.




drill question 1, create a class for a cat shelter? Think of the attribute you can put into the class to represent the data of a cat. Some attributes like owner telephone and address should be set as private, and accompany by the neccesary get and set function.

drill question 2, create bank account objects with classes as specified in DS03 Objects Q3.


Notice from the code I posted, I have to manually track the objects, manually remember what objects I have created and use it.
In programming, the ability to link one topic learned previously to another topic, "mesh" the knowledge together is very important. So to speak.
From data structures , we know that it is convenient to manipulate data in a data structure, and depends on the condition we can choose the best data structure to represent the data. Can we "link" class&objects with data structures?

Refer to the code below,






Drill question 3. Based on the class you have created, can you store the objects in a data structure of your choice???? Think of what are the possible applications for data structures "meshing" with class&objects?
HINT: try to use constructors


below is the code for the SpStudent class in the slides, with my comments

[FYP] climbing up a ramp

well done boys and girls~! We shall not stop here. There are more to come..... 

RAWWRRRRRR

[FYP] almost there

turning the segway using a pot while maintaing balance