C++ Program For Removing Every K-th Node Of The Linked List

// C++ program to delete every k-th 
// Node of a singly linked list.
#include<bits/stdc++.h>
using namespace std;

// Linked list Node 
struct Node
{
    int data;
    struct Node* next;
};

// To remove complete list (Needed 
// for case when k is 1)
void freeList(Node *node)
{
    while (node != NULL)
    {
        Node *next = node->next;
        delete (node);
        node  = next;
    }
}

// Deletes every k-th node and returns head
// of modified list.
Node *deleteKthNode(struct Node *head, 
                    int k)
{
    // If linked list is empty
    if (head == NULL)
        return NULL;

    if (k == 1)
    {
       freeList(head);
       return NULL;
    }

    // Initialize ptr and prev before 
    // starting traversal.
    struct Node *ptr = head, *prev = NULL;

    // Traverse list and delete every 
    // k-th node
    int count = 0;
    while (ptr != NULL)
    {
        // Increment Node count
        count++;

        // Check if count is equal to k
        // if yes, then delete current Node
        if (k == count)
        {
            // Put the next of current Node in
            // the next of previous Node
            delete(prev->next);
            prev->next = ptr->next;

            // Set count = 0 to reach further
            // k-th Node
            count = 0;
        }

        // Update prev if count is not 0
        if (count != 0)
            prev = ptr;

        ptr = prev->next;
    }

    return head;
}

// Function to print linked list
void displayList(struct Node *head)
{
    struct Node *temp = head;
    while (temp != NULL)
    {
        cout << temp->data << " ";
        temp = temp->next;
    }
}

// Utility function to create 
// a new node.
struct Node *newNode(int x)
{
    Node *temp = new Node;
    temp->data = x;
    temp->next = NULL;
    return temp;
}

// Driver code
int main()
{
    // Start with the empty list 
    struct Node* head = newNode(1);
    head->next = newNode(2);
    head->next->next = newNode(3);
    head->next->next->next = newNode(4);
    head->next->next->next->next = 
    newNode(5);
    head->next->next->next->next->next = 
    newNode(6);
    head->next->next->next->next->next->next =
    newNode(7);
    head->next->next->next->next->next->next->next =
    newNode(8);

    int k = 3;
    head = deleteKthNode(head, k);

    displayList(head);

    return 0;
}