Computer Programming

In a single channel contention based medium access control (MAC) protocols, whenever more than one station or node tries to access the medium at the same instant of time, it leads to packet collisions. If the collided stations tries to access the channel again, the packets will collide as the nodes are synchrozied in time. So the nodes need to be displaced in time. To displace them temporally, a backoff algorithm is used (example binary exponential backoff (BEB)). For example, in BEB algorithm, whenever a node's transmission is involved in a collision with another node's transmission, both nodes will choose a random waiting time and wait for this amoiunt of time before attempting again. If they are not successful in this attempt, they double their contention window and choose a randoim waiting time before transmitting again. This process will be repeated for certain number of attempts. If the nodes are not successful in their transmission after this limit, the packets will be dropped from their queue. Answered by C. Rama Krishna, NITTTR, Chandigarh, India on 03.12.2008 at 11.40 AM (IST)

it is the transmission of microwaves. One person throws a microwave to another person and so on.

for two positive integers:

public static int gcd(int i1, int i2) {

// using Euclid's algorithm

int a=i1, b=i2, temp;

while (b!=0) {

temp=b;

b=a%temp;

a=temp;

}

return a;

}

The question itself is a bit vague since it doesn't suggest whether you're asking about the types of trees or the operations which can be performed on trees.

A tree is a data structure which stores information in a logical way that typically is ideally suited for searching quickly, often by ordering the nodes or items of the tree, also ideally, nodes should be able to be added to or removed from a tree quickly and efficiently. Often, trees are chosen as a means of simply structuring data in a meaningful way with no concerns as to their performance.

When trees are chosen as an alternative to a list, the reason for this is to gain the benefits of rapid insertion, searching and deletion of nodes. Common tree structures for this purpose are the binary tree and the black and red tree. A binary tree has an extremely simple and extremely fast method of searching for data, but it is highly dependent on nodes being added in an order which is somewhat random. If ordered data is added to a tree, the depth of the tree will be linear, thereby providing no benefits over a linked list in addition, removal of nodes can cause a binary tree to have to be rebuilt as all the nodes beneath the deleted node will have to be re-added to the tree, typically under different nodes, commonly causing linear branches of the tree and slowing down application performance.

R&B trees were designed to address many of the issues of a binary tree. By developing a data structure which intentionally keeps the depth of the tree shallow, high speed searching and node removal can be achieved, but at a cost to the insertion algorithm which is designed to "shake things up" a little. R&B trees are far beyond the scope of this answer.

General trees are used less as a means of providing ideal performance but instead are intended as a means of providing structure for data. General trees store information in a way which reflects the data format itself. An example of a general tree is the file system of a disk drive. The root directory contains zero or more children which each contain zero or more children which each contain zero or

more... you get the point. This structure is also used for things like the abstract syntax tree of a compiler. Source code is parsed into "tokens" which are the structured as nodes of a tree which are then "walked" when optimizing and producing binary code.

There are many more types of trees. Many of which ate covered by Donald Knuth in extensive, if not insane detail in "The Art of Computer Programming".

Among the operations you'd perform on the tree are insertion, deletion, searching, walking, reduction, simplification and more.

The simple answer is you don't. The primary purpose of a flowchart is to show the flow of execution through an algorithm, with all primary functions and decisions described in broad, abstract terms.

There is no need to distinguish between local and global variables because that is an implementation detail -- it's far too low-level a concept for algorithm design.

All variables utilised by an algorithm should essentially be declared up front at the start of the flowchart and should therefore be treated as being local to that particular flowchart. It doesn't matter where those variables came from, only that they be initialised accordingly. The decision to make a variable global comes much later, once the interactions between different flowcharts have been established. Even so, a global variable should only ever be considered when the variable represents a truly global concept. In the vast majority of cases, passing arguments into functions is often the better option. Especially when separate algorithms are intended to run concurrently because making a global variable thread-safe can seriously impact performance. But this is not a concern in algorithm design, they are only of importance to the implementers; the class designers.

To find the GCD of three numbers, a, b and c, you need to find the GCD of a and b first, such that d = GCD(a, b). Then call GCD(d, c). Although you could simply call GCD(GCD(a, b), c), a more useful method is to use an array and iteratively call the GCD(a, b) function, such that a and b are the first two numbers in the first iteration, which becomes a in the next iteration, while b is the next number. The following program demonstarates this method.

Note that the GCD of two numbers can either be calculated recursively or iteratively. This program includes both options, depending on whether RECURSIVE is defined or not. In a working program you'd use one or the other, but the iterative approach is usually faster because it requires just one function call and no additional stack space.

The program will create 10 random arrays of integers of length 3 to 5 and process each in turn. Note that the more numbers in the array, the more likely the GCD will be 1.

#include<iostream>

#include<time.h>

#define RECURSIVE // comment out to use iterative method

#define ARRAY // comment out to use non-arrays

#ifdef RECURSIVE

// Returns the GCD of the two given integers (recursive method)

unsigned int gcd(unsigned int a, unsigned int b)

{

if(!a)

return(b);

if(!b)

return(a);

if(a==b)

return(a);

if(~a&1)

{

if(b&1)

return(gcd(a>>1,b));

else

return(gcd(a>>1,b>>1)<<1);

}

if(~b&1)

return(gcd(a,b>>1));

if(a>b)

return(gcd((a-b)>>1,b));

return(gcd((b-a)>>1,a));

}

#else

// Returns the GCD of the two given integers (iterative method)

unsigned int gcd(unsigned int a, unsigned int b)

{

if(!a)

return(b);

if(!b)

return(a);

int c;

for(c=0; ((a|b)&1)==0; ++c)

{

a>>=1;

b>>=1;

}

while((a&1)==0)

a>>=1;

do{

while((b&1)==0)

b>>=1;

if(a>b)

{

unsigned int t=a;

a=b;

b=t;

}

b-=a;

}while(b);

return(a<<c);

}

#endif RECURSIVE

// Returns the greatest common divisor in the given array

unsigned int gcd(const unsigned int n[], const unsigned int size)

{

if( size==0 )

return( 0 );

if( size==1 )

return( n[0] );

unsigned int hcf=gcd(n[0],n[1]);

for( unsigned int index=2; index<size; ++index )

hcf=gcd(hcf,n[index]);

return(hcf);

}

int main()

{

using std::cout;

using std::endl;

srand((unsigned) time(NULL));

for(unsigned int attempt=0; attempt<10; ++attempt)

{

unsigned int size=rand()%3+3;

unsigned int* num = new unsigned int[size];

unsigned int index=0;

while(index<size)

num[index++]=rand()%100;

unsigned int hcf=gcd(num,size);

cout<<"GCD(";

index=0;

cout<<num[index];

while(++index<size)

cout<<','<<num[index];

cout<<") = "<<hcf<<endl;

delete[]num;

}

cout<<endl;

}

Because registers are where all the actual work is done by the CPU. Think of registers as being a bank of switches which can be configured so the CPU can perform a specific operation upon a specific set of operands, be they values or memory addresses where values can be found. Some operations have no operands while others have one or two, but in order for the CPU to know which operation and which operands it should operate upon the registers must be set accordingly. The CPU achieves this through a repeating fetch-decode-execute cycle, fetching the next instruction, decoding its operands and then executing the instruction. In a multi-threaded environment, the CPU must also save the state of the registers to allow another thread to restore those registers for itself. In this way, a single CPU can switch from one thread to another and pick up from exactly where it left off.

Java.

While Visual Basic is certainly useful for writing Windows applications, that's all it can do. If you want the same program to run on other platforms (such as Linux), the entire program must be re-written from scratch.

With Java, there is no need to convert. Once compiled, Java programs can be executed upon any platform that has a suitable Java virtual machine implementation, which is pretty much everything today.

prod=0;

i=1;

do

{

prod = prod +a[i] * b[i];

i=i+1;

} while(i<=20);

There are three types of toolbar as written bellow : 1. Menu Bar
2. Docked Toolbar
3. Built-in Toolbar.

You can create a separate string initially empty. Then using a loop, start at the end of the string and add it to the end of the other string. At the end of the loop, the other string would contain the reverse.

#include<stdio.h>

#include<conio.h>

void main()

{

char a[5][10];

int i;

clrscr();

for(i=0;i<5;i++)

{

printf("enter %d string",i+1);

scanf("%s",&a[i]);

}

for(i=0;i<5;i++)

{

printf("\n%s",a[i]);

}

getch();

}

Registers are storage locations internal the the processor. CPU instructions operate on these values directly. On RISC processors, all data must be moved into a register before it can be operated. On CISC (Intel) chips, there are a few operations that can load data from RAM, process it, and save the result back out, but the fastest operations work directly with registers.

Also, there are registers that are set aside for certain tasks, these generally include a program counter, stack, and flags.

Each register also has a size that determines the maximum amount of data that can be processed at a time. The registers on Pentium chips, for example, are 32 bits.

Finally, there are generally only a few registers available on a processer. Intel chips, for example, have 6 general purpose registers, and several specialized registers including a base register, stack register, flags register, program counter, and some addressing registers.

Memory, or RAM, is located external to the CPU. Generally speaking, data has to be loaded into a CPU register from memory before the CPU can process it, RAM is much slower than registers, there is a lot more RAM than registers, and generally memory can be addressed on a byte boundaries, where registers may not be able to access all the bytes in a register.

To summarize: in general, registers are temporary storage in the CPU that holds the data the processor is currently working on, while RAM holds the program instructions and the data the program requires.

Hopefuly this helps,

--Eric Tolman

Start

Input a

if a%3 = 0 then

Print a

else

print" enter another number"

end

1. start

2. Input N

3. if N<3, go to step 6

4. if N%3 && N%6!=0 then

print N

5. N=N-3 go to step 3

6. end

in the cpu, or central processing unit

he made an acount were he documented his money and then he gained intrest then 500 years later he had billions and made Microsoft

Yes, a computer can count. You could get a computer to count forever, if you wanted to. All a computer does is compute information. So yes, you could get a computer to count. But, wouldn't your fingers suffice?

Multiply the area of the base by the height of the object. The area of the base can be found by multiplying the length times the width of one of the faces.

An algorithm simply describes the finite, procedural steps required to solve a problem. Algorithms are not specific to any one programming language, but without algorithms there would be no computer programs let alone programming languages. That is, you cannot program a computer to solve a problem unless you know how to solve the problem yourself and for that you need to know the algorithm. Once you have the algorithm, you can program the computer to implement it.