Given a circular singly linked list containing N nodes, the task is to remove all the nodes from the list which contains Fibonacci data values.
Examples:
Input: CLL = 9 -> 11 -> 34 -> 6 -> 13 -> 20
Output: 9 -> 11 -> 6 -> 20
Explanation:
The list contains 2 fibonacci data values 32 and 13.
Therefore, the nodes containing this data has been deleted
Input: 5 -> 11 -> 16 -> 21 -> 17 -> 10
Output: 11 -> 16 -> 17 -> 10
Explanation:
The list contains 2 fibonacci data values 5 and 21.
Therefore, the nodes containing this data has been deleted
Approach: The idea is to use hashing to precompute and store the Fibonacci numbers, and then check if a node contains a Fibonacci value in O(1) time.
- Traverse through the entire circular singly linked list and obtain the maximum value in the list.
- Now, in order to check for the Fibonacci numbers, build a hash table containing all the Fibonacci numbers less than or equal to the maximum value in the circular singly linked list.
- Finally, traverse the nodes of the circular singly linked list one by one and check if the node contains Fibonacci numbers as their data value. Remove the nodes which have Fibonacci value.
Below is the implementation of the above idea:
// C++ program to delete all the // Fibonacci nodes from the // circular singly linked list #include <bits/stdc++.h> using namespace std;
// Structure for a node struct Node {
int data;
struct Node* next;
}; // Function to insert a node at the beginning // of a Circular linked list void push( struct Node** head_ref, int data)
{ // Create a new node and make head as next
// of it.
struct Node* ptr1
= ( struct Node*) malloc (
sizeof ( struct Node));
struct Node* temp = *head_ref;
ptr1->data = data;
ptr1->next = *head_ref;
// If linked list is not NULL then
// set the next of last node
if (*head_ref != NULL) {
// Find the node before head
// and update next of it.
while (temp->next != *head_ref)
temp = temp->next;
temp->next = ptr1;
}
else
// Point for the first node
ptr1->next = ptr1;
*head_ref = ptr1;
} // Delete the node from a Circular Linked list void deleteNode(Node* head_ref, Node* del)
{ struct Node* temp = head_ref;
// If node to be deleted is head node
if (head_ref == del)
head_ref = del->next;
// Traverse list till not found
// delete node
while (temp->next != del) {
temp = temp->next;
}
// Copy the address of the node
temp->next = del->next;
// Finally, free the memory
// occupied by del
free (del);
return ;
} // Function to find the maximum // node of the circular linked list int largestElement( struct Node* head_ref)
{ // Pointer for traversing
struct Node* current;
// Initialize head to the current pointer
current = head_ref;
// Initialize min int value to max
int maxEle = INT_MIN;
// While the last node is not reached
do {
// If current node data is
// greater for max then replace it
if (current->data > maxEle) {
maxEle = current->data;
}
current = current->next;
} while (current != head_ref);
return maxEle;
} // Function to create hash table to // check Fibonacci numbers void createHash(set< int >& hash,
int maxElement)
{ int prev = 0, curr = 1;
// Adding the first two elements
// to the hash
hash.insert(prev);
hash.insert(curr);
// Inserting the Fibonacci numbers
// into the hash
while (curr <= maxElement) {
int temp = curr + prev;
hash.insert(temp);
prev = curr;
curr = temp;
}
} // Function to delete all the Fibonacci nodes // from the singly circular linked list void deleteFibonacciNodes(Node* head)
{ // Find the largest node value
// in Circular Linked List
int maxEle = largestElement(head);
// Creating a hash containing
// all the Fibonacci numbers
// upto the maximum data value
// in the circular linked list
set< int > hash;
createHash(hash, maxEle);
struct Node* ptr = head;
struct Node* next;
// Traverse the list till the end
do {
// If the node's data is Fibonacci,
// delete node 'ptr'
if (hash.find(ptr->data)
!= hash.end())
deleteNode(head, ptr);
// Point to the next node
next = ptr->next;
ptr = next;
} while (ptr != head);
} // Function to print nodes in a // given Circular linked list void printList( struct Node* head)
{ struct Node* temp = head;
if (head != NULL) {
do {
printf ( "%d " , temp->data);
temp = temp->next;
} while (temp != head);
}
} // Driver code int main()
{ // Initialize lists as empty
struct Node* head = NULL;
// Created linked list will be
// 9->11->34->6->13->20
push(&head, 20);
push(&head, 13);
push(&head, 6);
push(&head, 34);
push(&head, 11);
push(&head, 9);
deleteFibonacciNodes(head);
printList(head);
return 0;
} |
// Java program to delete all the // Fibonacci nodes from the // circular singly linked list import java.util.*;
class GFG{
// Structure for a node static class Node {
int data;
Node next;
}; // Function to insert a node at the beginning // of a Circular linked list static Node push(Node head_ref, int data)
{ // Create a new node and make head as next
// of it.
Node ptr1 = new Node();
Node temp = head_ref;
ptr1.data = data;
ptr1.next = head_ref;
// If linked list is not null then
// set the next of last node
if (head_ref != null ) {
// Find the node before head
// and update next of it.
while (temp.next != head_ref)
temp = temp.next;
temp.next = ptr1;
}
else
// Point for the first node
ptr1.next = ptr1;
head_ref = ptr1;
return head_ref;
} // Delete the node from a Circular Linked list static void deleteNode(Node head_ref, Node del)
{ Node temp = head_ref;
// If node to be deleted is head node
if (head_ref == del)
head_ref = del.next;
// Traverse list till not found
// delete node
while (temp.next != del) {
temp = temp.next;
}
// Copy the address of the node
temp.next = del.next;
// Finally, free the memory
// occupied by del
del = null ;
return ;
} // Function to find the maximum // node of the circular linked list static int largestElement(Node head_ref)
{ // Pointer for traversing
Node current;
// Initialize head to the current pointer
current = head_ref;
// Initialize min int value to max
int maxEle = Integer.MIN_VALUE;
// While the last node is not reached
do {
// If current node data is
// greater for max then replace it
if (current.data > maxEle) {
maxEle = current.data;
}
current = current.next;
} while (current != head_ref);
return maxEle;
} // Function to create hash table to // check Fibonacci numbers static void createHash(HashSet<Integer> hash,
int maxElement)
{ int prev = 0 , curr = 1 ;
// Adding the first two elements
// to the hash
hash.add(prev);
hash.add(curr);
// Inserting the Fibonacci numbers
// into the hash
while (curr <= maxElement) {
int temp = curr + prev;
hash.add(temp);
prev = curr;
curr = temp;
}
} // Function to delete all the Fibonacci nodes // from the singly circular linked list static void deleteFibonacciNodes(Node head)
{ // Find the largest node value
// in Circular Linked List
int maxEle = largestElement(head);
// Creating a hash containing
// all the Fibonacci numbers
// upto the maximum data value
// in the circular linked list
HashSet<Integer> hash = new HashSet<Integer>();
createHash(hash, maxEle);
Node ptr = head;
Node next;
// Traverse the list till the end
do {
// If the node's data is Fibonacci,
// delete node 'ptr'
if (hash.contains(ptr.data))
deleteNode(head, ptr);
// Point to the next node
next = ptr.next;
ptr = next;
} while (ptr != head);
} // Function to print nodes in a // given Circular linked list static void printList(Node head)
{ Node temp = head;
if (head != null ) {
do {
System.out.printf( "%d " , temp.data);
temp = temp.next;
} while (temp != head);
}
} // Driver code public static void main(String[] args)
{ // Initialize lists as empty
Node head = null ;
// Created linked list will be
// 9.11.34.6.13.20
head = push(head, 20 );
head = push(head, 13 );
head = push(head, 6 );
head = push(head, 34 );
head = push(head, 11 );
head = push(head, 9 );
deleteFibonacciNodes(head);
printList(head);
} } // This code is contributed by 29AjayKumar |
# Python3 program to delete all the # Fibonacci nodes from the # circular singly linked list # Structure for a node class Node:
def __init__( self ):
self .data = 0
self . next = None
# Function to add a node at the beginning # of a Circular linked list def push(head_ref, data):
# Create a new node and make head as next
# of it.
ptr1 = Node()
temp = head_ref;
ptr1.data = data;
ptr1. next = head_ref;
# If linked list is not None then
# set the next of last node
if (head_ref ! = None ):
# Find the node before head
# and update next of it.
while (temp. next ! = head_ref):
temp = temp. next ;
temp. next = ptr1;
else :
# Point for the first node
ptr1. next = ptr1;
head_ref = ptr1;
return head_ref
# Delete the node from a Circular Linked list def deleteNode( head_ref, delt):
temp = head_ref;
# If node to be deleted is head node
if (head_ref = = delt):
head_ref = delt. next ;
# Traverse list till not found
# delete node
while (temp. next ! = delt):
temp = temp. next ;
# Copy the address of the node
temp. next = delt. next ;
# Finally, free the memory
# occupied by delt
del (delt);
return ;
# Function to find the maximum # node of the circular linked list def largestElement( head_ref):
# Pointer for traversing
current = None
# Initialize head to the current pointer
current = head_ref;
# Initialize min value to max
maxEle = - 10000000
# While the last node is not reached
while ( True ):
# If current node data is
# greater for max then replace it
if (current.data > maxEle):
maxEle = current.data;
current = current. next ;
if (current = = head_ref):
break
return maxEle;
# Function to create hashmap table to # check Fibonacci numbers def createHash(hashmap, maxElement):
prev = 0
curr = 1 ;
# Adding the first two elements
# to the hashmap
hashmap.add(prev);
hashmap.add(curr);
# Inserting the Fibonacci numbers
# into the hashmap
while (curr < = maxElement):
temp = curr + prev;
hashmap.add(temp);
prev = curr;
curr = temp;
# Function to delete all the Fibonacci nodes # from the singly circular linked list def deleteFibonacciNodes( head):
# Find the largest node value
# in Circular Linked List
maxEle = largestElement(head);
# Creating a hashmap containing
# all the Fibonacci numbers
# upto the maximum data value
# in the circular linked list
hashmap = set ()
createHash(hashmap, maxEle);
ptr = head;
next = None
# Traverse the list till the end
while ( True ):
# If the node's data is Fibonacci,
# delete node 'ptr'
if (ptr.data in hashmap):
deleteNode(head, ptr);
# Point to the next node
next = ptr. next ;
ptr = next ;
if (ptr = = head):
break
# Function to print nodes in a # given Circular linked list def printList( head):
temp = head;
if (head ! = None ):
while ( True ):
print (temp.data, end = ' ' )
temp = temp. next
if (temp = = head):
break
# Driver code if __name__ = = '__main__' :
# Initialize lists as empty
head = None ;
# Created linked list will be
# 9.11.34.6.13.20
head = push(head, 20 );
head = push(head, 13 );
head = push(head, 6 );
head = push(head, 34 );
head = push(head, 11 );
head = push(head, 9 );
deleteFibonacciNodes(head);
printList(head);
# This code is contributed by rutvik_56 |
// C# program to delete all the // Fibonacci nodes from the // circular singly linked list using System;
using System.Collections.Generic;
class GFG{
// Structure for a node class Node {
public int data;
public Node next;
}; // Function to insert a node at the beginning // of a Circular linked list static Node push(Node head_ref, int data)
{ // Create a new node and make head as next
// of it.
Node ptr1 = new Node();
Node temp = head_ref;
ptr1.data = data;
ptr1.next = head_ref;
// If linked list is not null then
// set the next of last node
if (head_ref != null ) {
// Find the node before head
// and update next of it.
while (temp.next != head_ref)
temp = temp.next;
temp.next = ptr1;
}
else
// Point for the first node
ptr1.next = ptr1;
head_ref = ptr1;
return head_ref;
} // Delete the node from a Circular Linked list static void deleteNode(Node head_ref, Node del)
{ Node temp = head_ref;
// If node to be deleted is head node
if (head_ref == del)
head_ref = del.next;
// Traverse list till not found
// delete node
while (temp.next != del) {
temp = temp.next;
}
// Copy the address of the node
temp.next = del.next;
// Finally, free the memory
// occupied by del
del = null ;
return ;
} // Function to find the maximum // node of the circular linked list static int largestElement(Node head_ref)
{ // Pointer for traversing
Node current;
// Initialize head to the current pointer
current = head_ref;
// Initialize min int value to max
int maxEle = int .MinValue;
// While the last node is not reached
do {
// If current node data is
// greater for max then replace it
if (current.data > maxEle) {
maxEle = current.data;
}
current = current.next;
} while (current != head_ref);
return maxEle;
} // Function to create hash table to // check Fibonacci numbers static void createHash(HashSet< int > hash,
int maxElement)
{ int prev = 0, curr = 1;
// Adding the first two elements
// to the hash
hash.Add(prev);
hash.Add(curr);
// Inserting the Fibonacci numbers
// into the hash
while (curr <= maxElement) {
int temp = curr + prev;
hash.Add(temp);
prev = curr;
curr = temp;
}
} // Function to delete all the Fibonacci nodes // from the singly circular linked list static void deleteFibonacciNodes(Node head)
{ // Find the largest node value
// in Circular Linked List
int maxEle = largestElement(head);
// Creating a hash containing
// all the Fibonacci numbers
// upto the maximum data value
// in the circular linked list
HashSet< int > hash = new HashSet< int >();
createHash(hash, maxEle);
Node ptr = head;
Node next;
// Traverse the list till the end
do {
// If the node's data is Fibonacci,
// delete node 'ptr'
if (hash.Contains(ptr.data))
deleteNode(head, ptr);
// Point to the next node
next = ptr.next;
ptr = next;
} while (ptr != head);
} // Function to print nodes in a // given Circular linked list static void printList(Node head)
{ Node temp = head;
if (head != null ) {
do {
Console.Write( "{0} " , temp.data);
temp = temp.next;
} while (temp != head);
}
} // Driver code public static void Main(String[] args)
{ // Initialize lists as empty
Node head = null ;
// Created linked list will be
// 9.11.34.6.13.20
head = push(head, 20);
head = push(head, 13);
head = push(head, 6);
head = push(head, 34);
head = push(head, 11);
head = push(head, 9);
deleteFibonacciNodes(head);
printList(head);
} } // This code is contributed by PrinciRaj1992 |
<script> // javascript program to delete all the // Fibonacci nodes from the // circular singly linked list // Structure for a node
class Node { constructor() {
this .data = 0;
this .next = null ;
}
} // Function to insert a node at the beginning
// of a Circular linked list
function push(head_ref , data) {
// Create a new node and make head as next
// of it.
var ptr1 = new Node();
var temp = head_ref;
ptr1.data = data;
ptr1.next = head_ref;
// If linked list is not null then
// set the next of last node
if (head_ref != null ) {
// Find the node before head
// and update next of it.
while (temp.next != head_ref)
temp = temp.next;
temp.next = ptr1;
} else
// Point for the first node
ptr1.next = ptr1;
head_ref = ptr1;
return head_ref;
}
// Delete the node from a Circular Linked list
function deleteNode(head_ref, del) {
var temp = head_ref;
// If node to be deleted is head node
if (head_ref == del)
head_ref = del.next;
// Traverse list till not found
// delete node
while (temp.next != del) {
temp = temp.next;
}
// Copy the address of the node
temp.next = del.next;
// Finally, free the memory
// occupied by del
del = null ;
return ;
}
// Function to find the maximum
// node of the circular linked list
function largestElement(head_ref) {
// Pointer for traversing
var current;
// Initialize head to the current pointer
current = head_ref;
// Initialize min var value to max
var maxEle = Number.MIN_VALUE;
// While the last node is not reached
do {
// If current node data is
// greater for max then replace it
if (current.data > maxEle) {
maxEle = current.data;
}
current = current.next;
} while (current != head_ref);
return maxEle;
}
// Function to create hash table to
// check Fibonacci numbers
function createHash( hash , maxElement) {
var prev = 0, curr = 1;
// Adding the first two elements
// to the hash
hash.add(prev);
hash.add(curr);
// Inserting the Fibonacci numbers
// into the hash
while (curr <= maxElement) {
var temp = curr + prev;
hash.add(temp);
prev = curr;
curr = temp;
}
}
// Function to delete all the Fibonacci nodes
// from the singly circular linked list
function deleteFibonacciNodes(head) {
// Find the largest node value
// in Circular Linked List
var maxEle = largestElement(head);
// Creating a hash containing
// all the Fibonacci numbers
// upto the maximum data value
// in the circular linked list
var hash = new Set();
createHash(hash, maxEle);
var ptr = head;
var next;
// Traverse the list till the end
do {
// If the node's data is Fibonacci,
// delete node 'ptr'
if (hash.has(ptr.data))
deleteNode(head, ptr);
// Point to the next node
next = ptr.next;
ptr = next;
} while (ptr != head);
}
// Function to print nodes in a
// given Circular linked list
function printList(head) {
var temp = head;
if (head != null ) {
do {
document.write(temp.data+ " " );
temp = temp.next;
} while (temp != head);
}
}
// Driver code
// Initialize lists as empty
var head = null ;
// Created linked list will be
// 9.11.34.6.13.20
head = push(head, 20);
head = push(head, 13);
head = push(head, 6);
head = push(head, 34);
head = push(head, 11);
head = push(head, 9);
deleteFibonacciNodes(head);
printList(head);
// This code contributed by aashish1995 </script> |
9 11 6 20
Time Complexity: O(n + log(maxElement)) (actual generation hash table of fibonacci no. till maxElement required O(log(maxElement)) time + O(n) for traversing LinkList containing node n)
Auxiliary Space: O(log(maxElement)) (storing fibonacci number’s in hash)