DataStructures In C#: Part I

What are DataStructures?

Data structures

are abstract structures, or classes, that are used to organize data and provide a set of operations that can be performed upon this data.

Everyone's Favorite Linear, Direct Access, Homogeneous Data Structure

Simplest and most widely used data structures in computer programs

Contents are stored in contiguous memory

Homogeneous data structures

Creating an Array

arrayName = new arrayType<allocationSize>;

booleanArray = new bool<10>;

This allocates a contiguous block of memory in the CLR-managed heap, large enough to hold the allocationSize number of

arrayTypes.

Types Of Arrays

Plain Arrays

Jagged Arrays

Stack

The next and more serious data structure

System.Collections.Stack

class -- .NET Framework Base Class Library

	It is a FILO (First In, Last Out) It has only one point where data enters or leaves Default capacity is 10 elements Can't insert or remove elements into or from the middle of the stack Methods available are push(...), pop(), and isEmpty()
	Popping an item removes the item from the top of the stack.

A Stack can be visualized graphically as a vertical collection of items. When an item is pushed onto the stack, it is placed on top of all other items.

Example

public

class pArrayStack

{

// declare some properties

protected object<> data;

protected int pointer;

/**

* construct a new stack given the capacity

*/

public pArrayStack(int capacity)

{

// initialize data array with given capacity

data = new object;

// start with an empty stack

pointer = 0;

}

 

/**

* push an object onto the stack

*/

public void push(object o)

{

// check if there is enough space

if(pointer < data.Length)

data = o;

}

/**

* pop an object from the stack

*/

public object pop()

{

// check if stack is empty

if(isEmpty())

return null;

// get object to be returned

object o = data<--pointer>;

// null out memory location

data = null;

// return object we got

return o;

}

}

}

Program calling above class file is

//Stack

DataStructures.pArrayStackTest st = new pArrayStackTest();

// create a stack with maximum capacity 10

pArrayStack stack = new pArrayStack(10);

// push 10 elements onto the stack

for

(int i=0;i<10;i++){

// make a string "objN" where N ranges 0 to 9

string

objToPush = "obj" + i;

// push the object on the stack

stack.push(objToPush); }

// pop all elements from the stack

while

(!stack.isEmpty()) {

// pop an object from the stack

string

objPoped = (string)stack.pop();

// display what we're doing

Console.WriteLine("poping: {0}",objPoped); }

**Watch out for the next article in the series where the author shall discuss the Queue type of Data Structure.