Friday, February 5
Introduction to Data structure
Data structure is a way to organized data in some way so that we can perform operations on the data in effective way.Some examples are listed below.
- Link List.
- Stack.
- Queue.
- Tree.
- Graph.
- Hash Table.
1) Size of data.
2) Amount of data.
For Implementing Data structure We need to understand Dynamic Memory Allocation
Pointers - A pointer is variable which contain the memory address of another variable.
Declaration Of Pointer variable -
int a; // Normal variable Declaration
int *a; // Pointer Variable Declaration
Operators Of Pointer -
- & - Address Operator
- * - Value at the address operator
Example of Pointer -
#include<stdio.h> // Header files
Void main()
{
int a=5;
int *p ;
p = &a ;
printf("\n %d",a); // 5
printf("\n %d",p); // address 25001
printf("\n %u",&a); //25001
printf("\n %u",&a); // 25002
printf("\n %d",*p); // 5
printf("\n %d",*(&a)); // 5
return 0;
}
Dynamic Memory Allocation
- sizeof()
- malloc()
- calloc()
- free()
sizeoff()
The size of operation is use to find the size of argument in terms of byte . the argument can be variable or any data type.
Example.
int a[10] ;
sizeof(a); // 20
sizeof(float); // 4
malloc()
This function is use to allocate the memory space.
Syntax - ptr =(data type *) malloc( specific size) ;
Example.
ptr =(int*) malloc(10) ;
Calloc()
This function is used to allocate the multiple blocks of memory.
syntax - ptr = (int*) calloc( number of block , size of block ) ;
Example.
ptr =(int*) calloc ( 5 , 2) ; // this allocate 5 blocks , each of 2 bytes
free()
This function is use to release the memory spaces.
Syntax - free(ptr);
Example.
free(ptr) ; // memory set to free
we would like to have an interactive session. comment your questions below.
