C program to implement linked list using struct

Structure in C programming language is a composite data type that can hold variables of more than one data type and keyword struct is use to declare structure in C.

Syntax to define struct in C programming language is as:

struct [structure_tag]
{
    //datatype variable 1
    //int x;
    //char s;
    ...
}[structure_variables];

I will assume that you know how to implement struct normally in C programming language because here I am going to cover how to implement struct using linked list

C Program for struct using linked list:

#include<stdio.h>

#include<conio.h>

#include<stdlib.h>

//...............................................Function Creation...........................................//

void createlinkedlist();

void display();

void insert_at_first();

void delete_from_first();

void delete_from_end();

void insert_at_selected_position();

void delete_entire_list();

void reverse_nodes();

//.........................................structure node...............................................//

struct node

{

int roll;

char name[30];

struct node *next;

};

struct node *head;

//......................................................MAIN..............................................//

int main()

{

int ch;

do

{

printf("\n\n\n\n\n\n\t\t\t1.Create Linked list");

printf("\n\t\t\t2.Display List");

if(head!=NULL)

{

printf("\n\t\t\t3.Delete From First\t");

printf("\n\t\t\t4.Delete From end\t");

printf("\n\t\t\t5.Insert at first\t");

printf("\n\t\t\t6.Insert at selected position");

printf("\n\t\t\t7.Delete entire List");

printf("\n\t\t\t8.Reverse List");

}

printf("\n\t\t\t9.Exit\t");

scanf("%d",&ch);

switch(ch)

{

case 1:

createlinkedlist();

break;

case 2:

display();

break;

case 9:

exit (0);

break;

case 5:

insert_at_first();

break;

case 3:

delete_from_first();

break;

case 4:

delete_from_end();

break;

case 6:

insert_at_selected_position();

break;

case 7:

delete_entire_list();

break;

case 8:

reverse_list();

break;

default:

printf("Wrong choice Try again......");

}

}while(ch!=3);

}

//............................................Create linked list.................................................//

void createlinkedlist()

{

system("cls");

struct node *newnode,*temp;

newnode=(struct node*)malloc(sizeof(struct node));

printf("\n\n\t\t\tRoll : ");

scanf("%d",&newnode->roll);

printf("\t\t\tName : ");

scanf("%s",&newnode->name);

newnode->next=NULL;

if(head==NULL)

{

head=newnode;

}

else

{

temp=head;

while(temp->next!=NULL)

{

temp=temp->next;

}

temp->next=newnode;

}

}

// ......................................................DISPLAY............................................//

void display()

{

system("cls");

struct node *temp;

printf("\n\n\t\t\tRoll\t\tName\n");

if(head!=NULL)

{

for(temp=head;temp!=NULL;temp=temp->next)

printf("\t\t\t%d\t\t%s\n",temp->roll,temp->name);

}

else

{

printf("\n\t\t\tList is empty Boss... %c %c ",2,2);

}

}

//............................................Insert At FIrst.................................................//

void insert_at_first()

{

system("cls");

struct node *temp,*newnode;

newnode=(struct student *)malloc(sizeof(struct node));

printf("\n\n\t\t\tRoll : ");

scanf("%d",&newnode->roll);

printf("\t\t\tName : ");

scanf("%s",&newnode->name);

temp=head;

head=newnode;

newnode->next=temp;

return 0;

}

//..............................................Delete from first.....................................................//

void delete_from_first()

{

system("cls");

struct node *temp;

if(head==NULL)

{

printf("\n\t\t\tList is empty Boss... %c %c ",2,2);

}

else

{

temp=head;

free(head);

head=temp->next;

printf("\n\n\t\t\tFirst list deleted from node...");

}

return 0;

}

//..............................................Delete from end................................................//

void delete_from_end()

{

system("cls");

struct node *temp,*newtemp;

temp=head;

while(temp->next!=NULL)

{

newtemp=temp;

temp=temp->next;

if(temp->next==NULL)

newtemp->next=NULL;

}

free(temp);

printf("\n\n\t\t\tLast node is deleted....");

return 0;

}

//..................................................Insert at selected position....................................//

void insert_at_selected_position()

{

struct node *temp;

struct node *new_temp,*temp_copy;

temp=head;

int position,i;

printf("\n\n\t\t\tEnter the roll before you want to insert\t");

scanf("%d",&position);

for(i=1;i<position;i++)

{

temp=temp->next;

}

temp_copy=temp->next;

new_temp=(struct node *)malloc(sizeof(struct node));

temp->next=new_temp;

printf("\n\n\t\t\tRoll : ");

scanf("%d",&new_temp->roll);

printf("\t\t\tName : ");

scanf("%s",&new_temp->name);

new_temp->next=temp_copy;

return 0;

}

//..................................................free entire list........................................//

void delete_entire_list()

{

system("cls");

struct node *temp,*had;

temp=head;

if(temp->next==NULL)

{

free(temp);

}

else

{

while(temp!=NULL)

{

had=temp;

temp=temp->next;

free(had);

}

}

head=NULL;

return 0;

}

//.......................................Reverse List....................................//

void reverse_list()

{

system("cls");

if(head->next==NULL)

{

printf("\n\n\tsorry BOSS %c reverse not possible...",1);

}

else

{

struct node *p1,*p2,*p3;

p1=head;

p2=p1->next;

p3=p1->next->next;

p1->next=NULL;

while(p3!=NULL)

{

p2->next=p1;

p1=p2;

p2=p3;

p3=p3->next;

}

p2->next=p1;

head=p2;

}

}