Data structure used: Singly linked list where each node contains a data element say data, and the address of the immediate next node say next, with Head holding the address of the first node.
Recursive function to print alternative nodes (Pseudocode):
Function alternate_display(temp):
Begin
IF(temp!=NULL){
Print "temp->data"
If(temp->next==NULL)
temp=NULL;
Else
alternate_display(temp->next->next);
}
Else
return control to the main function
End IF-ELSE
End FUNCTION
C Implementation:
#include <stdio.h>
#include <stdlib.h>
typedef struct list //node structure
{
int data;
struct list *next;
}node;
//recursive function
void alternatedisp(node *temp);
int main(){
node *head=NULL,*temp,*temp1;
int choice,count=0,key;
//Taking the linked list as input
do
{
temp=(node *)malloc(sizeof(node));
if(temp!=NULL)
{
printf("\nEnter the element in the list : ");
scanf("%d",&temp->data);
temp->next=NULL;
if(head==NULL)
{
head=temp;
}
else
{
temp1=head;
while(temp1->next!=NULL)
{
temp1=temp1->next;
}
temp1->next=temp;
}
}
else
{
printf("\nMemory not avilable...node allocation is not possible");
}
printf("\nIf you wish to add m ore data on the list enter 1 : ");
scanf("%d",&choice);
}while(choice==1);
//Now displaying the alternative nodes starting from the begining
printf("\nDisplaying the alternative items of the list starting from the begining : \n");
alternatedisp(head);
printf("NULL\n");
return 0;
}
//recursive function to display alternative nodes
void alternatedisp(node *temp)
{
if(temp!=NULL)
{
printf("%d->",temp->data);
if(temp->next==NULL)
temp=NULL;
else
alternatedisp(temp->next->next);
}
else
return;
}
Output
Enter the element in the list : 7
If you wish to add m ore data on the list enter 1 : 1
Enter the element in the list : 6
If you wish to add m ore data on the list enter 1 : 1
Enter the element in the list : 5
If you wish to add m ore data on the list enter 1 : 1
Enter the element in the list : 4
If you wish to add m ore data on the list enter 1 : 1
Enter the element in the list : 3
If you wish to add m ore data on the list enter 1 : 0
Displaying the alternative items of the list starting from the begining :
7->5->3->NULL
Data structure used: Singly linked list where each node contains a data element say data, and the address of the immediate next node say next, with Head holding the address of the first node.
Recursive function to print alternative nodes (Pseudocode):
C Implementation:
Output