Lock a folder in win 7 or Xp

>>Make a folder in C drive Rename it as your wish gor eg "abc" without quotes
>>Now open command prompt(press windows+R)
>>Type "attrib +s +h C:\file name\ press Enter key [file name as u created i c drive.. eg abc]
>>This command will make folder invisible and it can't be seen even in hidden files and folders
>>T o make it visible again
                Type   attrib -s -h C:\file name\

Note:
Folder name is ur password..........
Now problem is that how to clear Run history, because it is visible to all.

See my next post

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Window tricks

Hi frnds.......
I'm back with some tricks to boost your knowledge.......

=> To increase RAM virtually for better performance of your computer
>>Right click on my computer icon on Desktop
>>Goto properties
>>Goto advanced system settings
>>Goto performance-settings
>>Goto advanced
>>Goto virtual memory-change
>>Custom size
Keep the initial size of ram as recomended and maximum size double of it ....... then Restart your computer

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Tricks

if u have sony laptop or any other  having win 7..... 64 or( 32bit [ sony])  operating system then  NOT to WORRY ABOUT C++ compiler installation,  contact 9779402356.....9356057604

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INHERITANCE continued

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As we know derived class inherit all the features of Base class  and it also add its own features ,data etc  .............
When a class is inherited all the functions and data member are inherited, although not all of them will be accessible by the member functions of the derived class. But there are some exceptions to ........................

Some of the exceptions to be noted in C++ inheritance are as follows.

• The constructor and destructor of a base class are not inherited
• the assignment operator is not inherited
• the friend functions and friend classes of the base class are also not inherited.

 There are some points to be remembered about C++ inheritance. The protected and public variables or members of the base class are all accessible in the derived class. But a private member variable not accessible by a derived class.

It is a well known fact that the private and protected members are not accessible outside the class. But a derived class is given access to protected members of the base class

In C++ there are three inheritance access specifiers:

• public
• protected
• private

Any of these three inheritance access specifiers can be modified with the virtual keyword. In my experience interviewing candidates for c++ positions, I've learned that the average programmer does not know how these are used, or even what they mean. So I thought I would go over them here.
The three access modifiers public, protected and private are analogous to the access modifiers used for class members.

public

When a base class is specified as public ie: class c : public base {}; the base class can be seen by anyone who has access to the derived class. That is, any members inherited from base can be seen by code accessing c.

protected

When a base class is specified as protected ie: class c : protected base {}; the base class can only be seen by subclasses of C.

private

When a base class is specified as private ie: class c : private base {}; the base class can only be seen by the class C itself.

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INHERITANCE

Inheritance is the process by which new classes called derived classes are created from existing classes called base classes. The derived classes have all the features or some of the features of the base class and the programmer can choose to add new features specific to the newly created derived class.

For example, a programmer can create a base class named fruit and define derived classes as mango, orange, banana, etc. Each of these derived classes, (mango, orange, banana, etc.) has all the features of the base class (fruit) with additional attributes or features specific to these newly created derived classes. Mango would have its own defined features, orange would have its own defined features, banana would have its own defined features, etc.


This concept of Inheritance leads to the concept of polymorphism.

Features or Advantages of Inheritance:

1)Reusability:
Inheritance helps the code to be reused in many situations. The base class is defined and once it is compiled, it need not be reworked. Using the concept of inheritance, the programmer can create as many derived classes from the base class as needed while adding specific features to each derived class as needed.
2)Saves Time and Effort:

The above concept of reusability achieved by inheritance saves the programmer time and effort. Since the main code written can be reused in various situations as needed.

3)Increases Program Structure which results in greater reliability.

General Format for implementing the concept of Inheritance:

class derived_classname: access specifier baseclassname

Properties of access specifier:

If a member or variables defined in a class is private, then they are accessible by members of the same class only and cannot be accessed from outside the class. .

Public members and variables are accessible from outside the class.

Protected access specifier is a stage between private and public. If a member functions or variables defined in a class are protected, then they cannot be accessed from outside the class but can be accessed from the derived class.

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Fibonacci using copy constructor

#include"iostream.h"
#incl:
#include<conio.h>
class fibonacci
{
int f,x,y;
public:
fibonacci()
{
f=0;
x=1;
y=f+x;
}
fibonacci (fibonacci &g)
{
   f=g.f;
x=g.x;
y=g.y;
}
void find()
{
  f=x;
x=y;
y=f+x;
}

void dis()
{
cout<<y<<"\n";
}
};
vboid main(void)
{
fibonacci num;
for(i=0;i<=12;i++)
{
num.dis();
num.find();
}
}

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Reverse a no in c++

#include"iostream.h"
#include<conio.h>
class rev
{
int a;
public:
void akhi()
{
cout<<"enter any no\n";
cin>>a;
}
void lesh()
{
int rev=0,rem;
while(a>0)
{
rem=a%10;
a=a/10;
rev=(rev*10)+rem;
}
Cout<<"\n  reverse is "<<rev;
}
};

void main()
{
clrscr();
rev k;
k.akhi();
k.lesh();
getch();
}

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Hanoi Algo

                       Tower  Of  Hanoi

Tower of Hanoi is a mathematical game or puzzle invented by french mathematician in 1983.

a)It consists of three rods, suppose A , B , C . And contains a number of disks of different sizes which can slide from one rod to another.
b)Disks are arranged in ascending order from the top i.e. smallest one is at the top.
(No need to confuse you are thinking that all three rods contains disks......Absolutely No....Actually the first Rod(A) contains the disks in ascending order and our goal is to move or transfer or arrange all disks from rod A to Rod C in ascending order via rod B )

now we have fixed no of tower i.e.3 but the no of disks varies up to 9(max no disks) .....................
if we have 3 disks then we have to complete in 7 moves only.....
samer as  for  4= 15 moves
               5=31 moves
               6=63 moves
............................
.............................
i.e. in general 2^n-1 , where n=no of disks.

We have to follow the following rules for moving disks......

1)Only one disk may be moved at a time
2)Each move consists of taking the upper disk frm one of the rod and sliding it onto another rod.
3)No disk may be placed on top of a smaller disk.

First u try by taking 3 disks.... Once you become master in solving the game with 3 disks then u can solve it for any no of disks.......

for n= 3
1)A -> c
2)A -> B
3)C -> B
4)A -> C
5)B -> A
6)B -> C
7)A -> c


http://www.towerofhanoi.net/
We have 7 valid moves.

Some tips:
(Alternate moves between the smallest disk and a non smallest disk, when smallest disk alw  moving the s)ays move it in the same direction)  ..... leave it if u not understood.

see.... if the starting no of disk is even (4,6...) move to the right..... if the starting no of disk is odd move it to the left.... if there is no rod in the chosen direction i.e. left move it to the opposite end but further move it in correct direction to compensate...........

See in general........................
1)To move N disk frm A to C
2)Move n-1 dosk frm A to B this leaves disk N alone on rod A.
3)Move disk N frm A to C.
4)Move n-1 disk frm B to C , so they sit on N.

The concept is that n-1 disk in rod B is considered as a fresh problem and can be solved in the same manner.......................(Recursion-Repetition of some particular steps untill we get the result).

[Disk 1 is moved to rod C if N is odd ,and to Rod 2 if n is even]
www.chessandpoker.com/tower-of-hanoi

TOWER(N,A,B,C)
1) If N=0,then: Return (No disks persent)
2)repeat steps 3 to 5 for K=N,N-1,N-2..........1.
3)Tower function(K-1,A,C,B)
4)Write:A  -> C
5) [Interchange A and B]
Set TEMP:=A,A=B.
    B:=TEMP.
  [End of STEP 2loop]

6)RETURN

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C++ tutes 4u: Get started

C++ tutes 4u: Get started

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SOME BASIC TERMS

PROGRAM : A program is a sequence of instruction that can be executed by a computer or u can say a program is a set of an executable statement.

I am communicating with u in english because u are able to understand english language.
Think if we wish to talk or communicate with computer then  in which language we have to give instruction  and the ans is "binary language"
but as we know it is not possible to remember all binary that's why we give instruction in High level language in the form of "program".
But still there is one problem computer don't understand "program" it understand binary number, so we need an interface to convert "source code" into "Objectcode".......and that interface is compiler.

COMPILER :A compiler is a software system which converts the source code into object  or
                    Human acceptable language(HIGH level language) into machine acceptable language(binary number or low level language),that the computer operating system can then run.

SOURCECODE : Coding of program in any high level programming language.
        eg -
#include"iostream.h" 
void main()
{ int x=10;                cout<<"\n\t\t\t\n\n"<<x;            }

OBJECTCODE : Objectcode is simply set of instruction in binary number. It is formed after the compilation of sourcecode..

Now supose teacher asked u to solve a problem then obiously u need a paper to write  in the same manner here  to write and edit the program u need "TEXT EDITOR".

TEXT EDITOR : It is a software system that allows u to create and edit text files on your computer.
                              Programmers uses text editor to write programs in a programming language  such as  c++.

CONSOLE PROGRAM : Console programs or applications are that which uses text to communicate with the user and to show their results  i.e. which uses command line for input and output rather than graphical user interface (G.U.I.).

"High level langusges are machine independent"

There is three basi steps of software design :-
1)Flowchart
2)Algorithm
3)Coding

Steps in developing a program :-
1)Program design(development of a strategy to be used in writing the program)
2)Program coding
3)Program testing(includes detecting and removing error)


That's why we install a TC software...........................
Few examples of compiler :-
1)Turboo c++
2)Borland
3)Zortech
4)Dev c++
4)Intel C++
4)Microsoft c++

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More basic continued...............

Binary conversion 101

In normal numbers a value like 456 is made up of  4*100+5*10+6*1. This is a base 10 number . 10112 is a base 2 number which is equal to 8*1+4*0+2*1+1*1=11 in base 10.
Most programmer'sdon't need or use binary, but in C it can be a useful skill to have.

How Big is a Program?

Computers program can be as small as a few hundred bytes or as large as a few billions bytes. When a
Program is loaded into RAM from Disk the pattern of the bits is copied exactly, even one bit wrong can cause the program to fail.
Computer hardware has been engineered so this doesn't happen.
If an Application (say VLC player) 40 megabytes in size, then roughly 320 million bits are coppied into  RAM.

Bit is nothing , it is either 0 or 1 and 8 bits constitute 1 BYTE.
1024 BYTE =1Kb(Kilobytes) roughly 1000=10^3.
1024 Kb=1Mb   roughly   1000=10^3 Kb=1Mb=10^3*10^3bytes=1Mb=10^6
Same as 1024 Mb=1Gb=10^9 bytes
also 10^12 bytes = 1Tb(Tera byte)
=1000000000000   individuals  ON/OFF  switches !

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Some more Basic

Learn about hardware and how it runs software
A computer is a physical collection of bits that u can touch. The screen , main system box , keyboard ,mouse etc. and inside this there is software ......................
Computer is made up of following parts:
1)CPU
2)ROM that holds permanently stored instructions
3)RAM that holds software and data
4)I/O devices
5)Permanent storage devices eg. Hard disk ,Floopy disk etc
But What exactly is Software?
It is the combination of instructions and data known as MACHINE CODE .
that forms the building blocks of application.
Such as games,word processor,Vlc etc
This machine code lives in the memory of the computer as billions of little on - off switches...............

THE CPU IS THE BRAIN
The heart of the computer is the Cpu plus RAM .The Cpu fetches data from Ram,carries out  operations on data and then stores it back in ram . The cpu also fetch data from permanent storage such as ROM ,hard disk etc.
The data in memory is organised in blocks of 8 switches ,each switches is known as bit and a block is a byte.Each bit can be on or off.
when a bit is on it has the value 1 when its off it has the value 0. this is called binary notation. there are 256 different combinations of 8 bits with the value 0 to 255.................

Table of bit values................................
00000000 -> 0
00000001 -> 1
00000010 -> 2
------------------
------------------
------------------
------------------
11111111 -> 255

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OVERVIEW OF C++

c++ is powerful programming language that had attracted worldwide attention because the software had adopted c++ language .
c++ languaage is portable,portability means that a program written in c++ for one machine can be transferred to another machine with minimum change or no change


HISTORICAL BACKGROUND OF C++
c++ WAS developed by bajarne stroustrup at bell-laboratories in 1980. It contains the best fearures of simula 67 and C and designed a language which support OOP features.
therefore we can say that C++ is an extention of C language .
Since the class was a major addition to original C language,Stroustrup called the new language "C with classes".......However in 1983 the name was changed to c++. The idea of c++ comes from c increment operator(++).

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C++ tutes 4u: Get started

C++ tutes 4u: Get started

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Get started

well c++ is concerned with computer, so first we should know what is computer how it works.
As u all know that "Computer is an electronic device which gives output only when we give instruction  to it" . The instruction we give is in the form of PROGRAM.
let me clear it Wha t is program?
PROGRAM: It is a sequence of instructions that can be executed by a computer or u can say that "a program is a set of an executable statement"
Every program is written in some programming language.C++ is one of the most powerful programming language available.


Now i stopping our discussion on c++ for a while.
As written above that computer works only when we give instruction to it, now think when we give power to CPU then computer starts functioning and after a minutes a window opens.
My question is that how it works or frm where it is instructed for this task
POWER GIVEN TO CPU->Booting takes place->AND COMPUTER OPENS
ANS IS--->>>when a  computer is manufactured ,at that time manufacturers install a software in a BIOS setup (basic  input output system) whis is read by non volatile temporary memory ROM.


A computer is consist of three layers:
1)Hardware
2)Systemsoftware(O.S. :-Windows,Linux...........................)
3)Applicationsoftware(Vlc,Adobe................................)
After that users come......................................................................................


Now u all know that computer reads  or understand machine language or binary language also called
low level language(OBJECT CODE) i.e.(0 1) for eg when we press 2 from keyboard then it is converted in to binary number  1 0  in the same way when we prees 15 then it is converted in to 1111 and  when we press  A then it is converted in to 1000001 because the ASCII code of A is 65. we will discuss later about ASCII code.....................
Binary language is called LOW LEVEL LANGUAGE , c/c++/java.............. are HIGH LEVEL LANGUAGE.
NOW my question is when computer reads binary language then why we study HIGH LEVEL LANGUAGE ans is it is not possible to remember all binary codings ..... for example binary number of
55856985648788874  this is too large and it is not possible to remember.

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