Product of all prime nodes in a Doubly Linked List

0 0 8 minutes read

Given a doubly linked list containing N nodes. The task is to find the product of all prime nodes.

Example:

Input: List = 15 <=> 16 <=> 6 <=> 7 <=> 17
Output: Product of Prime Nodes: 119

Input: List = 5 <=> 3 <=> 4 <=> 2 <=> 9
Output: Product of Prime Nodes: 30

Approach:

Initialize a pointer temp with the head of the linked list and a product variable with 1.
Start traversing the linked list using a loop until all the nodes get traversed.
If node value is prime then multiply the value of the current node to the product i.e. product *= current_node-> data.
Increment the pointer to the next node of linked list i.e. temp = temp -> next.
Return the product.

Below is the implementation of the above approach:

C++

// C++ implementation to product all
// prime nodes from the doubly
// linked list
#include <bits/stdc++.h>
 
using namespace std;
 
// Node of the doubly linked list
struct Node {
    int data;
    Node *prev, *next;
};
 
// function to insert a node at the beginning
// of the Doubly Linked List
void push(Node** head_ref, int new_data)
{
    // allocate node
    Node* new_node = (Node*)malloc(sizeof(struct Node));
 
    // put in the data
    new_node->data = new_data;
 
    // since we are adding at the beginning,
    // prev is always NULL
    new_node->prev = NULL;
 
    // link the old list of the new node
    new_node->next = (*head_ref);
 
    // change prev of head node to new node
    if ((*head_ref) != NULL)
        (*head_ref)->prev = new_node;
 
    // move the head to point to the new node
    (*head_ref) = new_node;
}
 
// Function to check if a number is prime
bool isPrime(int n)
{
    // Corner cases
    if (n <= 1)
        return false;
    if (n <= 3)
        return true;
 
    // This is checked so that we can skip
    // middle five numbers in below loop
    if (n % 2 == 0 || n % 3 == 0)
        return false;
 
    for (int i = 5; i * i <= n; i = i + 6)
        if (n % i == 0 || n % (i + 2) == 0)
            return false;
 
    return true;
}
 
// function to product all prime nodes
// from the doubly linked list
int prodOfPrime(Node** head_ref)
{
    Node* ptr = *head_ref;
    Node* next;
    // variable prod = 1 for multiplying nodes value
    int prod = 1;
    // traverse list till last node
    while (ptr != NULL) {
        next = ptr->next;
        // if number is prime then
        // multiply to product
        if (isPrime(ptr->data))
            prod = prod * ptr->data;
        ptr = next;
    }
 
    // return product
    return prod;
}
 
// Driver program
int main()
{
    // start with the empty list
    Node* head = NULL;
 
    // create the doubly linked list
    // 15 <-> 16 <-> 7 <-> 6 <-> 17
    push(&head, 17);
    push(&head, 6);
    push(&head, 7);
    push(&head, 16);
    push(&head, 15);
    int prod = prodOfPrime(&head);
 
    cout << "Product of Prime Nodes : " << prod;
 
    return 0;
}

Java

// Java implementation to product all
// prime nodes from the doubly
// linked list
 
// Node of the doubly linked list
class Node
{
    int data;
    Node next, prev;
 
    Node(int d)
    {
        data = d;
        next = null;
        prev = null;
    }
}
 
class DLL 
{
    // function to insert a node at the beginning
    // of the Doubly Linked List
    static Node push(Node head, int data)
    {
        Node newNode = new Node(data);
        newNode.next = head;
        newNode.prev = null;
        if (head != null)
            head.prev = newNode;
        head = newNode;
 
        return head;
    }
 
    // Function to check if a number is prime
    static boolean isPrime(int n)
    {
        // Corner cases
        if (n <= 1)
            return false;
        if (n <= 3)
            return true;
 
        // This is checked so that we can skip
        // middle five numbers in below loop
        if (n % 2 == 0 || n % 3 == 0)
            return false;
 
        for (int i = 5; i * i <= n; i = i + 6)
            if (n % i == 0 || n % (i + 2) == 0)
                return false;
 
        return true;
    }
 
    // function to product all prime nodes
    // from the doubly linked list
    static int prodOfPrime(Node node)
    {
        // variable prod = 1 for multiplying nodes value
        int prod = 1;
         
        // traverse list till last node
        while (node != null)
        {
            // check is node value is Prime
            // if true then multiply to prod
            if (isPrime(node.data))
                prod *= node.data;
            node = node.next;
        }
        // return product
        return prod;
    }
 
    // Driver Program
    public static void main(String[] args)
    {
        // Start with empty list
        Node head = null;
 
        // create the doubly linked list
        // 15 <-> 16 <-> 7 <-> 6 <-> 17
        head = push(head, 17);
        head = push(head, 7);
        head = push(head, 6);
        head = push(head, 9);
        head = push(head, 10);
        head = push(head, 16);
        head = push(head, 15);
 
        int prod = prodOfPrime(head);
        System.out.println("Product of Prime Nodes: " + prod);
    }
}
 
// This code is contributed by Vivekkumar Singh

Python3

# Python3 implementation to product all
# prime nodes from the doubly
# linked list
 
# Node of the doubly linked list 
class Node: 
     
    def __init__(self, data): 
        self.data = data 
        self.prev = None
        self.next = None
 
# function to insert a node at the beginning
# of the Doubly Linked List
def push(head_ref, new_data):
 
    # allocate node
    new_node = Node(0)
 
    # put in the data
    new_node.data = new_data
 
    # since we are multiplying at the beginning,
    # prev is always None
    new_node.prev = None
 
    # link the old list of the new node
    new_node.next = (head_ref)
 
    # change prev of head node to new node
    if ((head_ref) != None):
        (head_ref).prev = new_node
 
    # move the head to point to the new node
    (head_ref) = new_node
    return head_ref
 
# Function to check if a number is prime
def isPrime(n):
 
    # Corner cases
    if (n <= 1):
        return False
    if (n <= 3):
        return True
 
    # This is checked so that we can skip
    # middle five numbers in below loop
    if (n % 2 == 0 or n % 3 == 0):
        return False
    i = 5
    while ( i * i <= n ):
        if (n % i == 0 or n % (i + 2) == 0):
            return False
        i += 6;
 
    return True
 
# function to product all prime nodes
# from the doubly linked list
def prodOfPrime(head_ref):
 
    ptr = head_ref
    next = None
     
    # variable prod = 1 for multiplying nodes value
    prod = 1
     
    # traverse list till last node
    while (ptr != None): 
        next = ptr.next
         
        # if number is prime then
        # multiply to product
        if (isPrime(ptr.data)):
            prod = prod * ptr.data
        ptr = next
 
    # return product
    return prod
 
# Driver Code
if __name__ == "__main__": 
 
    # start with the empty list
    head = None
 
    # create the doubly linked list
    # 15 <. 16 <. 7 <. 6 <. 17
    head = push(head, 17)
    head = push(head, 6)
    head = push(head, 7)
    head = push(head, 16)
    head = push(head, 15)
    prod = prodOfPrime(head)
 
    print("Product of Prime Nodes : ", prod)
 
# This code is contributed by Arnab Kundu

C#

// C# implementation to product all 
// prime nodes from the doubly 
// linked list 
using System;
 
// Node of the doubly linked list 
public class Node 
{ 
    public int data; 
    public Node next, prev; 
 
    public Node(int d) 
    { 
        data = d; 
        next = null; 
        prev = null; 
    } 
} 
 
class DLL 
{ 
    // function to insert a node at the beginning 
    // of the Doubly Linked List 
    static Node push(Node head, int data) 
    { 
        Node newNode = new Node(data); 
        newNode.next = head; 
        newNode.prev = null; 
        if (head != null) 
            head.prev = newNode; 
        head = newNode; 
 
        return head; 
    } 
 
    // Function to check if a number is prime 
    static Boolean isPrime(int n) 
    { 
        // Corner cases 
        if (n <= 1) 
            return false; 
        if (n <= 3) 
            return true; 
 
        // This is checked so that we can skip 
        // middle five numbers in below loop 
        if (n % 2 == 0 || n % 3 == 0) 
            return false; 
 
        for (int i = 5; i * i <= n; i = i + 6) 
            if (n % i == 0 || n % (i + 2) == 0) 
                return false; 
 
        return true; 
    } 
 
    // function to product all prime nodes 
    // from the doubly linked list 
    static int prodOfPrime(Node node) 
    { 
        // variable prod = 1 for multiplying nodes value 
        int prod = 1; 
         
        // traverse list till last node 
        while (node != null) 
        { 
            // check is node value is Prime 
            // if true then multiply to prod 
            if (isPrime(node.data)) 
                prod *= node.data; 
            node = node.next; 
        } 
        // return product 
        return prod; 
    } 
 
    // Driver code 
    public static void Main(String []args) 
    { 
        // Start with empty list 
        Node head = null; 
 
        // create the doubly linked list 
        // 15 <-> 16 <-> 7 <-> 6 <-> 17 
        head = push(head, 17); 
        head = push(head, 7); 
        head = push(head, 6); 
        head = push(head, 9); 
        head = push(head, 10); 
        head = push(head, 16); 
        head = push(head, 15); 
 
        int prod = prodOfPrime(head); 
        Console.WriteLine("Product of Prime Nodes: " + prod); 
    } 
} 
 
// This code is contributed by Arnab Kundu

Javascript

<script>
 
// JavaScript implementation to product all
// prime nodes from the doubly
// linked list
 
// Node of the doubly linked list
class Node {
    constructor(val) {
        this.data = val;
        this.prev = null;
        this.next = null;
    }
}
 
 
    // function to insert a node at the beginning
    // of the Doubly Linked List
    function push(head , data) {
    var newNode = new Node(data);
        newNode.next = head;
        newNode.prev = null;
        if (head != null)
            head.prev = newNode;
        head = newNode;
 
        return head;
    }
 
    // Function to check if a number is prime
    function isPrime(n) {
        // Corner cases
        if (n <= 1)
            return false;
        if (n <= 3)
            return true;
 
        // This is checked so that we can skip
        // middle five numbers in below loop
        if (n % 2 == 0 || n % 3 == 0)
            return false;
 
        for (i = 5; i * i <= n; i = i + 6)
            if (n % i == 0 || n % (i + 2) == 0)
                return false;
 
        return true;
    }
 
    // function to product all prime nodes
    // from the doubly linked list
    function prodOfPrime(node) {
        // variable prod = 1 for multiplying nodes value
        var prod = 1;
 
        // traverse list till last node
        while (node != null) {
            // check is node value is Prime
            // if true then multiply to prod
            if (isPrime(node.data))
                prod *= node.data;
            node = node.next;
        }
        // return product
        return prod;
    }
 
    // Driver Program
     
        // Start with empty list
        var head = null;
 
        // create the doubly linked list
        // 15 <-> 16 <-> 7 <-> 6 <-> 17
        head = push(head, 17);
        head = push(head, 7);
        head = push(head, 6);
        head = push(head, 9);
        head = push(head, 10);
        head = push(head, 16);
        head = push(head, 15);
 
        var prod = prodOfPrime(head);
        document.write("Product of Prime Nodes: " + prod);
 
// This code contributed by umadevi9616
 
</script>

Output

Product of Prime Nodes : 119

Complexity Analysis:

Time Complexity: O(N), where N is the number of nodes.
Space Complexity: O(1) because using constant variables

Feeling lost in the world of random DSA topics, wasting time without progress? It’s time for a change! Join our DSA course, where we’ll guide you on an exciting journey to master DSA efficiently and on schedule.
Ready to dive in? Explore our Free Demo Content and join our DSA course, trusted by over 100,000 zambiatek!