Linear Linked List

# include<stdio.h>
# include<conio.h>
# include<stdlib.h>
# include<alloc.h>
struct node
{
int info;
struct node *next;
}*list;
void append();
void addbeg();
void addafter();
void delet();
void search();
void update();
void display();
void main()
{
char ch;
int choice;
list = NULL; // Initialize list
do
{
clrscr();

printf("\n1. Append\t2. Add first\t3. Addafter\t4. Delete\t5. Search\t6.update\t 7. Display");

printf("\nEnter ur choice: ");
scanf("%d",&choice);
switch(choice)
{
case 1: append(); break;
case 2: addbeg(); break;

2

case 3: addafter(); break;
case 4: delet(); break;
case 5: search(); break;
case 6: update(); break;
case 7: display(); break;
default: printf("\nWrong choice.");
}
printf("\nDo u want to cnt....");
flushall();
ch=getche();
}while(ch == 'y');
}
void append() //Insert at the end of the list
{
int x;
struct node *p, *t;
char ch;
do
{
printf("\nEnter data : ");
scanf("%d",&x);
t = malloc(sizeof(struct node)); // create a node
t->info = x;
t->next = NULL;
if(list == NULL) // List is Empty
list=t;
else // List Not Empty
{
p= list;
while(p->next != NULL) // Find Last node
p = p->next;
p->next = t; // Link new node to last node
}
printf("\n Do u want to insert more? ");
flushall();
ch=getche();
}while(ch == 'y');
}

3

void addbeg() //Insert at the first position.
{
struct node *t;
int x;
char ch;
do
{
t = malloc(sizeof(struct node)); // Create a node
printf("\n Enter data : ");
scanf("%d",&x);
t->info = x;
t->next = list;
list = t;
printf("\n Do U want to insert more? ");
flushall();
ch=getche();
}while(ch=='y');
}
void addafter() // Insert at the specified location
{
struct node *p, *t;
int pos, x,i;
char ch;
do
{
printf("\n Enter data : ");
scanf("%d",&x);
t = malloc(sizeof(struct node));// Create a node
t->info = x;
printf("\n Enter position : ");
scanf("%d",&pos);
p=list;
for(i=1 ; i<pos ; i++) // To get position
{
if(p == NULL)
break;
else
p = p->next;
}

4

if(i==pos) // Position found
{
t->next = p->next; // Link new and right node
p->next = t; // link new and left node
}
else // Less elements
printf("\n less elements ");
printf("\n DO u want to insert more ? ");
flushall();
ch=getche();
} while(ch == 'y');
}
/***** Delete a node from linked list *****/
void delet()
{
struct node *p,*r;
int x;
char ch;
do
{
printf("\nEnter data to be deleted : ");
scanf("%d",&x);
p = list;
if(p == NULL)
{
printf(" \n List Empty");
break;
}
else if(p->info == x) // x found in first node
{
printf("\n%d has been deleted",p->info);
list = p->next;
free(p);
}
else
{
r = p; // r: previous node
p = p->next; // q: current node

5

while(p != NULL)

{
if(p->info == x) // x found
{
printf("\n %d has been deleted",p->info);
r->next = p->next;
free(p);
break;
}
else // x not found
{
r = p;
p = p->next;
}
}
if(p==NULL)
printf("\n %d not found",x);
}
printf("\nDO u want to delete more? ");
flushall();
ch=getche();
}while(ch == 'y');
}
/***** Search given element in a list *****/
void search()
{
int x;
char ch;
struct node *p;
do
{
p = list;
printf("\n Enter element to be searched: ");
scanf("%d",&x);

6

while(p != NULL)

{
if(p->info==x)
break;
else
p = p->next;
}
if(p!=NULL)
printf("\n%d found ",x);
else
printf("\n %d Not Found",x);
printf("\n Do you want to search another element? ");
flushall();
ch= getche();
} while(ch=='y');
}
/***** Update a value in a node *****/
void update()
{
int x,nv;
char ch;
struct node *p;
do
{
p = list;
printf("\n Enter element to be updated: ");
scanf("%d",&x);
printf("\n Enter new value: ");
scanf("%d",&nv);
while(p != NULL)
{
if(p->info==x)
{
p->info = nv;
break;
}
else
p = p->next;
}

7

if(p!=NULL)
printf("\n %d found and updated ",x);
else
printf("\n %d Not Found",x);
printf("\n Do you want to search another element? ");
flushall();
ch= getche();
} while(ch=='y');
}
void display()
{
struct node *p;
p = list;
if(p == NULL)
printf("\n List Empty ");
else
for( p = list ; p!=NULL ; p = p->next)
printf("\n%u %3d",p,p->info);
}