Notes

Singly Linked List

#include <stdio.h>
#include<malloc.h>

struct node
{
int info;
struct node *link;
};
typedef struct node *NODE;

NODE start = NULL;

NODE CreateNode ()
{
NODE z;
int item;

z = (NODE)malloc(sizeof(NODE));
if (z == NULL)
{
printf("Insufficient memory ");
exit ();
}
printf ("Enter item: ");
scanf ("%d", &item);
z->info = item;
z->link = NULL;
return z;
}

void FrontInsert()
{
NODE z;

z = CreateNode ();
if (start == NULL)
{
start = z;
return;
}
z->link = start;
start = z;
return;
}

void FrontDelete ()
{
NODE temp;

if (start == NULL)
{
printf("Empty Listn");
return;
}
else
{
temp = start;
start = start->link;
printf("The deleted item is : %dn", temp->info);
free (temp);
}
return;
}

void EndInsert()
{
NODE z, temp;

z = CreateNode();

if (start == NULL)
{
start = z;
return;
}

temp = start;
while (temp->link != NULL)
temp = temp->link;

temp->link = z;
return;
}

void EndDelete()
{
NODE prev, cur;

if(start == NULL)
{
printf ("Empty Listn");
return NULL;
}

prev = NULL;
cur = start;
while (cur->link != NULL)
{
prev = cur;
cur = cur->link;
}
prev->link = NULL;
printf("The deleted item is : %dn", cur->info);
free (cur);
return;
}

void Display ()
{
NODE temp;

if (start == NULL)
{
printf ("List is emptyn");
return;
}
temp = start;
printf ("The list is : ");
while (temp != NULL)
{
printf ("%dt", temp->info);
temp = temp->link;
}
return;
}

void main ()
{
int option, item;

clrscr();
printf ("Singly Linked List Operationsn");
printf ("-----------------------------n");
while (1)
{
printf ("nn1: Front Insertn2: Front Deleten");
printf ("3: End Insertn4: End Deleten");

printf ("nEnter Option :");
scanf ("%d", &option);

switch (option)
{
case 1:
FrontInsert ();
Display ();
break;
case 2:
FrontDelete ();
Display ();
break;
case 3:
EndInsert ();
Display ();
break;
case 4:
EndDelete ();
Display ();
break;
default:
exit(0);
}
}
}