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

// Javascript program to delete every 
// k-th Node of a singly linked list.
// Linked list Node 
class Node {
    constructor() {
        this.data = 0;
        this.next = null;
    }
}

// To remove complete list (Needed 
// for case when k is 1)
function freeList(node) {
    while (node != null) {
        next = node.next;
        node = next;
    }
    return node;
}

// Deletes every k-th node and
// returns head of modified list.
function deleteKthNode(head, k) {
    // If linked list is empty
    if (head == null)
        return null;

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

    // Initialize ptr and prev before
    // starting traversal.
    let ptr = head, prev = null;

    // Traverse list and delete
    // every k-th node
    let 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
            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 
function displayList(head) {
    temp = head;
    while (temp != null) {
        console.log(temp.data +
            " ");
        temp = temp.next;
    }
}

// Utility function to create a 
// new node.
function newNode(x) {
    temp = new Node();
    temp.data = x;
    temp.next = null;
    return temp;
}

// Driver Code
// Start with the empty list 
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);

let k = 3;
head = deleteKthNode(head, k);
displayList(head);
// This code is contributed by umadevi9616