Linked List Product of Nodes Between 0s

Given a linked list that contains a series of numbers separated by “0”. Multiply them and store them in the linked list in place.

Note: There will not be continuous zeros in the input.

Examples:  

Input  : 1->2->3->0->5->4->0->3->2->0
Output : 6->20->6

Input  : 1->2->3->4
Output : 1->2->3->4 

Approach: 

1. Start iterating over nodes of the linked list.
2. Iterate while temp.data !=0, and multiply these data into a variable ‘prod’.
3. When you encounter 0 as the node’s data, change pointers of previous nodes.

Below is the implementation of the above approach: 

C++

// C++ program to in-place product linked list
// nodes between 0s
#include<bits/stdc++.h>
using namespace std;

// Linked List Node
struct Node
{
    int data;
    Node* next;
    Node(int d)
    {
        data = d;
        next = NULL;
    }
};

// Function to traverse and print Linked List
    void printList(Node* head)
    {
        while (head->next != NULL)
        {
            cout<<head->data <<"-> ";
                head = head->next;
        }
        cout << head->data << "\n";
    }

// Function to in-place product linked list
// nodes between 0s

    // Function to store numbers till 0
    void inPlaceStore(Node* head)
    {
        if (head->data == 0)
        {
            head = head->next;
        }

        // To store modified list
        Node* res = head;

        // Traverse linked list and keep
        // adding nodes between 0s.
        Node* temp = head;
        int prod = 1;
        while (temp != NULL)
        {

            // loop to product the data of nodes till
            // it encounters 0
            if (temp->data != 0)
            {
                prod *= temp->data;
                temp = temp->next;
            }

            // If we encounters 0, we need
            // to update next pointers
            else
            {

                res->data = prod;
                res->next = temp->next;
                temp = temp->next;
                res = res->next;
                prod = 1;
            }
        }

        // For the last segment
        res->data = prod;
        res->next = temp;

        printList(head);
    }

    // Driver Code
    int main()
    {
        Node *head = new Node(3);
        head->next = new Node(2);
        head->next->next = new Node(0);
        head->next->next->next = new Node(4);
        head->next->next->next->next = new Node(5);
        head->next->next->next->next->next = new Node(0);
        head->next->next->next->next->next->next = new Node(6);
        head->next->next->next->next->next->next->next = new Node(7);
        inPlaceStore(head);
        return 0;
    }

// This code is contributed by Arnab Kundu

Java

// Java program to in-place product linked list
// nodes between 0s

// Linked List Node
class Node {
    int data;
    Node next;

    public Node(int data)
    {
        this.data = data;
        this.next = null;
    }
}

// Function to in-place product linked list
// nodes between 0s
public class inPlaceStoreLL {

    // Function to store numbers till 0
    static void inPlaceStore(Node head)
    {
        if (head.data == 0) {
            head = head.next;
        }

        // To store modified list
        Node res = head;

        // Traverse linked list and keep
        // adding nodes between 0s.
        Node temp = head;
        int prod = 1;
        while (temp != null) {

            // loop to product the data of nodes till
            // it encounters 0
            if (temp.data != 0) {
                prod *= temp.data;
                temp = temp.next;
            }

            // If we encounters 0, we need
            // to update next pointers
            else {

                res.data = prod;
                res.next = temp.next;
                temp = temp.next;
                res = res.next;
                prod = 1;
            }
        }

        // For the last segment
        res.data = prod;
        res.next = temp;

        printList(head);
    }

    // Function to traverse and print Linked List
    static void printList(Node head)
    {
        while (head.next != null) {
            System.out.print(head.data + "-> ");
            head = head.next;
        }
        System.out.println(head.data);
    }

    // Driver Code
    public static void main(String[] args)
    {
        Node head = new Node(3);
        head.next = new Node(2);
        head.next.next = new Node(0);
        head.next.next.next = new Node(4);
        head.next.next.next.next = new Node(5);
        head.next.next.next.next.next = new Node(0);
        head.next.next.next.next.next.next = new Node(6);
        head.next.next.next.next.next.next.next = new Node(7);
        inPlaceStore(head);
    }
}

Python3

# Python3 program to in-place
# product linked list nodes between 0s
import math

# Linked List Node
class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

# Function to traverse and print Linked List
def printList(head):
        while (head.next != None):
            print(head.data, end = "->")
            head = head.next

        print(head.data)
        print()

# Function to in-place product linked list
# nodes between 0s

# Function to store numbers till 0
def inPlaceStore(head):
        if (head.data == 0):
            head = head.next

        # To store modified list
        res = head

        # Traverse linked list and keep
        # adding nodes between 0s.
        temp = head
        prod = 1
        while (temp != None):

            # loop to product the data of nodes till
            # it encounters 0
            if (temp.data != 0):
                prod = prod * temp.data
                temp = temp.next

            # If we encounters 0, we need
            # to update next pointers
            else:

                res.data = prod
                res.next = temp.next
                temp = temp.next
                res = res.next
                prod = 1

        # For the last segment
        res.data = prod
        res.next = temp

        printList(head)

# Driver Code
if __name__=='__main__':
    head = Node(3)
    head.next = Node(2)
    head.next.next = Node(0)
    head.next.next.next = Node(4)
    head.next.next.next.next = Node(5)
    head.next.next.next.next.next = Node(0)
    head.next.next.next.next.next.next = Node(6)
    head.next.next.next.next.next.next.next = Node(7)
    inPlaceStore(head)

# This code is contributed by Srathore

C#

// C# program to in-place product linked list
// nodes between 0s
using System;

// Linked List Node
public class Node
{
    public int data;
    public Node next;

    public Node(int data)
    {
        this.data = data;
        this.next = null;
    }
}

// Function to in-place product linked list
// nodes between 0s
public class inPlaceStoreLL
{

    // Function to store numbers till 0
    static void inPlaceStore(Node head)
    {
        if (head.data == 0)
        {
            head = head.next;
        }

        // To store modified list
        Node res = head;

        // Traverse linked list and keep
        // adding nodes between 0s.
        Node temp = head;
        int prod = 1;
        while (temp != null)
        {

            // loop to product the data of nodes till
            // it encounters 0
            if (temp.data != 0)
            {
                prod *= temp.data;
                temp = temp.next;
            }

            // If we encounters 0, we need
            // to update next pointers
            else
            {

                res.data = prod;
                res.next = temp.next;
                temp = temp.next;
                res = res.next;
                prod = 1;
            }
        }

        // For the last segment
        res.data = prod;
        res.next = temp;

        printList(head);
    }

    // Function to traverse and print Linked List
    static void printList(Node head)
    {
        while (head.next != null)
        {
            Console.Write(head.data + "-> ");
            head = head.next;
        }
        Console.WriteLine(head.data);
    }

    // Driver Code
    public static void Main(String[] args)
    {
        Node head = new Node(3);
        head.next = new Node(2);
        head.next.next = new Node(0);
        head.next.next.next = new Node(4);
        head.next.next.next.next = new Node(5);
        head.next.next.next.next.next = new Node(0);
        head.next.next.next.next.next.next = new Node(6);
        head.next.next.next.next.next.next.next = new Node(7);
        inPlaceStore(head);
    }
}

// This code has been contributed by 29AjayKumar

Javascript

<script>
// javascript program to in-place product linked list
// nodes between 0s

// Linked List Node
    class Node {

         constructor(data) {
            this.data = data;
            this.next = null;
        }
    }

    // Function to in-place product linked list
    // nodes between 0s

    // Function to store numbers till 0
    function inPlaceStore(head) {
        if (head.data == 0) {
            head = head.next;
        }

        // To store modified list
        var res = head;

        // Traverse linked list and keep
        // adding nodes between 0s.
        var temp = head;
        var prod = 1;
        while (temp != null) {

            // loop to product the data of nodes till
            // it encounters 0
            if (temp.data != 0) {
                prod *= temp.data;
                temp = temp.next;
            }

            // If we encounters 0, we need
            // to update next pointers
            else {

                res.data = prod;
                res.next = temp.next;
                temp = temp.next;
                res = res.next;
                prod = 1;
            }
        }

        // For the last segment
        res.data = prod;
        res.next = temp;

        printList(head);
    }

    // Function to traverse and print Linked List
    function printList(head) {
        while (head.next != null) {
            document.write(head.data + "-> ");
            head = head.next;
        }
        document.write(head.data);
    }

    // Driver Code

        var head = new Node(3);
        head.next = new Node(2);
        head.next.next = new Node(0);
        head.next.next.next = new Node(4);
        head.next.next.next.next = new Node(5);
        head.next.next.next.next.next = new Node(0);
        head.next.next.next.next.next.next = new Node(6);
        head.next.next.next.next.next.next.next = new Node(7);
        inPlaceStore(head);

// This code contributed by Rajput-Ji
</script>

Output

6-> 20-> 42