# Delete Alternate Nodes of the Linked List

“** Delete Alternate Nodes of the Linked List**” is a basic problem exercise for beginners based on linked list. Here, we are given a linked list and our task is to delete every alternate node of a linked list.

For example, we need to delete every alternate nodes of the following linked list: LINKED LIST: 11 -> 12 -> 13 -> 14 -> 15 -> 16 After deleting every other alternate nodes of a linked list: LINKED LIST: 11 -> 13 -> 15

The steps required to delete alternate nodes of a linked list are as follows:

- If the linked list is empty, then return.
- Traverse the complete linked list.
- While traversing, keep track of previous node of the node to be deleted and then delete the node by releasing the memory allocated for the node.

**C++ Program to delete every alternate node of a linked list is as follows:**

/* C++ Program to delete alternate nodes of the Linked List */ #include<bits/stdc++.h> using namespace std; /* Structure of the node of the Linked List */ typedef struct node { int data; struct node *next; }Node; /* Function to Insert node at the end of the linked list */ void insertEnd(Node **head,int ele) { /* Creating a new node */ Node *new_node = new Node(); new_node -> data = ele; new_node -> next = NULL; /* check whether the linked list is empty or not */ /* If Linked List is empty, then new node will become head of the linked list */ if(*head == NULL) { (*head) = new_node; return; } /* If Linked List is not empty, then traverse the complete linked list and point the pointer of last node of the linked list to the new node */ Node *temp = (*head); while(temp->next != NULL) temp = temp -> next; temp -> next = new_node; } /* Function to Print the Linked List */ void print(Node *head) { Node *temp = head; while(temp != NULL) { cout << temp -> data << " "; temp = temp -> next; } cout<<endl; } /* Function to delete alternate nodes of the Linked List */ void deleteAlternate(Node *head) { /* If Linked List is empty, simply return */ if(head == NULL) return; Node *temp = head; /* keep track of previous node of the node to be deleted and then delete the node by releasing the memory allocated for the node. */ while(temp && temp->next) { Node *p = temp -> next; temp -> next = temp -> next -> next; temp = temp -> next; free(p); } } int main() { Node *head = NULL; /* Inserting Some Nodes in the Linked List */ insertEnd(&head,11); insertEnd(&head,12); insertEnd(&head,13); insertEnd(&head,14); insertEnd(&head,15); insertEnd(&head,16); cout<<"Before Deleting Alternate Nodes of the Linked List:\n"; print(head); deleteAlternate(head); cout<<"\nAfter Deleting Alternate Nodes of the Linked List:\n"; print(head); }

Before Deleting Alternate Nodes of the Linked List: 11 12 13 14 15 16 After Deleting Alternate Nodes of the Linked List: 11 13 15OUTPUT: