c program day-15

7/31/2019 C Program Day-15

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2/15

Explain link list

Explain linked list declaration

Traverse a linked list

Types of linked list

Insert nodes into a link list

Explain Data Structures


3/15

A data structure is a group of data elements grouped together under one

name. These data elements, known as members, can have different types and different

lengths.

syntax

struct structure_name {member_type1 member_name1;

member_type2 member_name2;

member_type3 member_name3;

} Stru_varname;

Where structure_name is a name for the structure type, stru_name can be a

set of valid identifiers for objects that have the type of this structure. Within braces { }

there is a list with the data members, each one is specified with a type and a valid

identifier as its name.


4/15

// program to Accept the employee details from the End user

#include

#include

#include

struct emp

{

int eno;

char ename[25];

int sal;};

void main()

{

struct emp *e;

char ch='y';

clrscr();

while(ch=='y')


5/15

{

e=(struct emp *) malloc(sizeof(struct emp));

printf("\n Enter the employee number");

scanf("%d",&e->eno);

printf("\n Enter the employee name");

scanf("%s",e->ename);

printf("\n Enter the employee salary");

scanf("%d",&e->sal);

printf("\n Do you wish to continue[Y/N]?");

fflush(stdin);scanf("%c",&ch);

}

getch();

}


6/15

LINKED LIST :

It is a dynamic data structure. This implementation uses pointers. Each element of the list is

called as node. Each element points to the next element. In linked list, a node can be inserted

or deleted at any position.

Basic Terms :

(i) Node (ii) Null Pointer (iii) External pointer

(iv) Empty List

Operation on Linked list :

(i) Creation (ii) Traversing

(iii) Insertion

(a) Insertion at beginning

(b) Insertion at end

(c) Insertion at any position

(iv) Searching

(v) Deletion

(a) Deletion at beginning

(b) Deletion at end

(c) Deletion at any position


7/15

Linked List Declaration

A linked list storing information of players of a cricket teamcan be declared as :

Note That next is declared

as a pointer to the structureplayer itself.

Remember, that the last

node in the list should have

its pointer, next, set to the

value NULL.


8/15

Diagrammatically


9/15

// program to Add New Records in Single linked list using First to// Last method simply defined as to form the new Datastructure#include#include#include

void accept();struct emp{int eno;char ename[25];int sal;struct emp *next;

};// start - Ist Record, New1 - Current record, Temp - prevoius recordstruct emp *start=NULL,*new1=NULL,*temp=NULL,*new2,*dptr;void main(){char ch='y';

int no,recno;clrscr();while(ch=='y'){new1=(struct emp *) malloc(sizeof(struct emp));printf("\n Enter the employee number");scanf("%d",&new1->eno);

Continued,


10/15


scanf("%s",new1->ename);


scanf("%d",&new1->sal);

if (start==NULL) // Give Ist record as Input,to enter the following if true

{

start=new1; //current record is assigned to start

start->next=NULL; //current record next is set to NULL.because it is a

// first record

temp=new1; //current record is assigned to temp(point previous record)

}

else

{

temp->next=new1; // new1 have a current record &assigned to prevoius

next

// have a NULL value changed to addresstemp=new1; //current i/p record is assigned to temp ex. 1st record to II

temp->next=NULL;

}

printf("\n Do you wish to continue[Y/N]?");

fflush(stdin);

scanf("%c",&ch);} Continued,


11/15


12/15

else if (recno==new2->eno && new2->next !=NULL) {

temp->next=new1;

new1->next=new2;

}

// to check if it is last record &also to insert that place.

else if (recno==new2->eno && new2->next==NULL)

{

new2->next=new1;

new1->next=NULL;}

temp=new2;

}

// display all records

for(new2=start;new2!=NULL; new2=new2->next) // new2 initialize Ist record

{

printf("\n %d %s %d",new2->eno,new2->ename,new2->sal);

}

Continued,


13/15

//Deletion process

printf("\n Enter the record number to delete");

scanf("%d",&recno);

for(new2=start;new2!=NULL;new2=new2->next)

{

if(recno==start->eno){

start=start->next;

}

else if (recno==new2->eno && new2->next !=NULL)

{

temp->next=new2->next;}

else if(recno==new2->eno && new2->next==NULL)

{temp->next=NULL;}

temp=new2;

}

//display all the records


{


}

Continued,


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// Modify process

printf("\n Enter the employee number to be modified");

scanf("%d",&no);

for(new1=start;new1!=NULL; new1=new1->next) //new1 init.Ist record & search

{

if (no==new1->eno)

{

printf("\n Enter the Empno,Empname and salary");

scanf("\n %d %s %d",&new1->eno,new1->ename,&new1->sal);

}

}

//display all the records


{


}

//Memory deallocating process

new1=start;

Continued,


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while(1){

if(new1==NULL)

break;

dptr=new1;

new1=new1->next;

free(dptr);}

dptr=NULL;

new1=NULL;

temp=NULL;

start=NULL;

}void accept()

{

new1=(struct emp *) malloc(sizeof(struct emp));

printf("\n Enter the employee number");

scanf("%d",&new1->eno);


scanf("%s",new1->ename);


scanf("%d",&new1->sal);}}

c program day-15

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