WAP to implement the concept of linked list through arrays.

# include<stdio.h>
# define MAX 20

int arr[MAX];
int n;  /*Total number of elements in the list */

main()
{
int  choice,item,pos;
while(1)
{
printf("1.Input list\n");
printf("2.Insert\n");
printf("3.Search\n");
printf("4.Delete\n");
printf("5.Display\n");
printf("6.Quit\n");
printf("Enter your choice : ");
scanf("%d",&choice);

switch(choice)
{
case 1:
printf("Enter the number of elements to be entered : ");
scanf("%d",&n);

input(n);
break;
case 2:
insert();
break;
case 3:
printf("Enter the element to be searched : ");
scanf("%d", &item);
pos = search(item);
if(pos >= 1)
printf("%d found at position %d\n",item,pos);
else
printf("Element not found\n");
break;
case 4:
del();
break;
case 5:
display();
break;
case 6:
exit();
break;
default:
printf("Wrong choice\n");
} /*End of switch */
}/*End of while */
}/*End of main() */

input()
{
int i;
for(i = 0; i< n ; i++)
{
printf("Input value for element %d : ", i+1);
scanf("%d", &arr[i]);
}
}/*End of input()*/

int search(int item)
{
int i;
for(i=0; i < n; i++)
{
if(item == arr[i])
return(i+1);
}
return(0);  /* If element not found */
}/*End of search()*/

insert()
{
int temp,item,position;
if(n == MAX)
{
printf("List overflow\n");
return;
}
printf("Enter position for insertion : ");
scanf("%d", &position);
printf("Enter the value : ");
scanf("%d",&item);
if(position > n+1 )
{
printf("Enter position less than or equal to %d\n",n+1);
return;
}
if( position == n+1 )  /*Insertion at the end */
{
arr[n] = item;
n = n+1;
return;
}
/* Insertion in between */
temp=n-1;
while( temp >= position-1)
{
arr[temp+1] = arr[temp];  /* shifting right */
temp --;
}
arr[position-1] = item;
n = n +1 ;
}/*End of insert()*/

del()
{
int temp,position,item;
if(n == 0)
{
printf("List underflow\n");
return 0;
}
printf("Enter the element to be deleted : ");
scanf("%d",&item);
if(item==arr[n-1]) /*Deletion at the end*/
{
n = n-1;
return;
}
position=search(item);
if(position==0)
{
printf("Element not present in array\n");
return;
}
/*Deletion in between */
temp=position-1;
while(temp <= n-1)
{
arr[temp] = arr[temp+1];  /* Shifting left */
temp ++;
}
n = n - 1 ;
}/*End of del()*/

display()
{
int i;
if(n==0)
{
printf("List is empty\n");
return;
}
for(i = 0; i< n; i++)
printf("Value at position %d : %d\n", i+1, arr[i]);
}/*End of display()*/